摘要：
Student Vladislav came to his programming exam completely unprepared as usual. He got a question about some strange algorithm on a graph — something t 阅读全文
摘要：
Oleg's favorite subjects are History and Math, and his favorite branch of mathematics is division. To improve his division skills, Oleg came up with $ 阅读全文
摘要：
You are given a string $s$ of even length $n$. String $s$ is binary, in other words, consists only of 0's and 1's. String $s$ has exactly $\frac{n}{2} 阅读全文