摘要：
链接： https://codeforces.com/contest/1279/problem/D 题意： Santa Claus has received letters from n different kids throughout this year. Of course, each kid 阅读全文
摘要：
链接： https://codeforces.com/contest/1279/problem/C 题意： Santa has to send presents to the kids. He has a large stack of n presents, numbered from 1 to n 阅读全文
摘要：
链接： https://codeforces.com/contest/1279/problem/B 题意： New Year is coming! Vasya has prepared a New Year's verse and wants to recite it in front of San 阅读全文
摘要：
链接： https://codeforces.com/contest/1279/problem/A 题意： Polycarp is sad — New Year is coming in few days but there is still no snow in his city. To brin 阅读全文