Mynavi Programming Contest 2021 (AtCoder Beginner Contest 201) A~E 题解
ABC201/Mynavi2021A~E[A-TinyArithmeticSequence](https://atcoder.jp/contests/abc201/tasks/abc201_a)题目大意输入格式输出格式样例分析代码[B-Doyouknowthesecondhighestmountain?](https://atcoder.jp/contests/abc201/tasks/abc20