Educational Codeforces Round 90 (Rated for Div. 2) 2020/6/25 RANK:3959 SOLVED:3 RATING CHANGE +516 https://www.cnblogs.com/hznumqf/p/13196646.html
CodeForces 掉分日志
原文：https://www.cnblogs.com/hznumqf/p/13196558.html
