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You are given an array of integers. Vasya can permute (change order) its integers. He wants to do it so that as many as possible integers will become 阅读全文
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Professor Dumbledore is helping Harry destroy the Horcruxes. He went to Gaunt Shack as he suspected a Horcrux to be present there. He saw Marvolo Gaun 阅读全文
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There is a youngster known for amateur propositions concerning several mathematical hard problems. Today he is going to prepare a thought-provoking pr 阅读全文
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KazaQ wears socks every day. Before the first day, he has nn pairs of socks in his closet, labeled from 11 to nn. Every morning, he would put on a pai 阅读全文
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Gildong is playing a video game called Block Adventure. In Block Adventure, there are nn columns of blocks in a row, and the columns are numbered from 阅读全文
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Dima worked all day and wrote down on a long paper strip his favorite number nnconsisting of ll digits. Unfortunately, the strip turned out to be so l 阅读全文
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Let's call (yet again) a string good if its length is even, and every character in odd position of this string is different from the next character (t 阅读全文