【Educational Codeforces Round 53 (Rated for Div. 2)】 A:https://www.cnblogs.com/myx12345/p/9853775.html B:https://www.cnblogs.com/myx12345/p/9853779.html C:https://www.cnblogs.com/myx12345/p/9853793.html D:https://www.cnblogs.com/myx12345/p/9858179.html E: F: G: