摘要：
The map of Berland is a rectangle of the size n × m, which consists of cells of size 1 × 1. Each cell is either land or water. The map is surrounded b 阅读全文
摘要：
Polycarp is a music editor at the radio station. He received a playlist for tomorrow, that can be represented as a sequence a1, a2, ..., an, where ai 阅读全文
摘要：
Modern text editors usually show some information regarding the document being edited. For example, the number of words, the number of pages, or the n 阅读全文
摘要：
There are three friend living on the straight line Ox in Lineland. The first friend lives at the point x1, the second friend lives at the pointx2, and 阅读全文