摘要：
Dima adds letters s1, …, sn one by one to the end of a word. After each letter, he asks Misha to tell him how many new palindrome substrings appeared 阅读全文
摘要：
The northern part of the Pyramid contains a very large and complicated labyrinth. The labyrinth is divided into square blocks, each of them either fil 阅读全文
摘要：
A positive integer is called a palindrome if its representation in the decimal system is the same when read from left to right and from right to left. 阅读全文