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At the children's day, the child came to Picks's house, and messed his house up. Picks was angry at him. A lot of important things were lost, in parti 阅读全文
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Palindromic characteristics of string s with length |s| is a sequence of |s| integers, where k-th number is the total number of non-empty substrings o 阅读全文
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The Cartesian coordinate system is set in the sky. There you can see n stars, the i-th has coordinates (xi, yi), a maximum brightness c, equal for all 阅读全文
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Some natural number was written on the board. Its sum of digits was not less than k. But you were distracted a bit, and someone changed this number to 阅读全文
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Two boys decided to compete in text typing on the site "Key races". During the competition, they have to type a text consisting of s characters. The f 阅读全文