摘要：
题目来源：http://codeforces.com/problemset/problem/58/A Vasya has recently learned to type and log on to the Internet. He immediately entered a chat room a 阅读全文
摘要：
题目来源：http://codeforces.com/problemset/problem/69/A A guy named Vasya attends the final grade of a high school. One day Vasya decided to watch a match 阅读全文