@[_rsy_](/user/46197) @[_bzy](/user/213388)
by Carroty_cat @ 2023-12-06 12:51:52
额，少了一句
`数据保证 $1 \leq n, m \leq 20000。`
by Carroty_cat @ 2023-12-06 13:17:01
@[Carroty_cat](/user/912750) fixed，感谢您的贡献。
by _bzy @ 2023-12-06 16:00:44