摘要： 题目链接； 题目描述： Petya loves lucky numbers very much. Everybody knows that lucky numbers are positive integers whose decimal record contains only the lucky 阅读全文

摘要： 题目链接； 题面： ...Once upon a time a man came to the sea. The sea was stormy and dark. The man started to call for the little mermaid to appear but alas, h 阅读全文