摘要：There are n cities numbered from 1 to n in Berland. Some of them are connected by two-way roads. Each road has its own length — an integer number from 阅读全文

摘要：A catenym is a pair of words separated by a period such that the last letter of the first word is the same as the last letter of the second. For examp 阅读全文

摘要：Bessie's been appointed the new watch-cow for the farm. Every night, it's her job to walk across the farm and make sure that no evildoers are doing an 阅读全文