[提高难度](https://www.luogu.com.cn/problem/list?difficulty=7&page=1)（确信）
by watermonster @ 2020-10-29 12:49:06
~~禁止无意义回复，谢谢qwq~~
by 听取MLE声一片 @ 2020-10-29 12:50:00
@[LSG_watermonster](/user/209454) ~~tg没这么水吧~~（滑稽）
by onginer @ 2020-10-29 12:52:32
p2572
by MatrixCascade @ 2020-10-29 13:08:43