B.这是个签到题

Status	Submit By	Time	Memory	Language	Code	Submit At
AC	mibbp	8ms	376 KiB		566 Bytes	2021-11-4 23:10:45
AC	mibbp	8ms	396 KiB		481 Bytes	2021-11-4 22:57:07
AC	albertzm	9ms	404 KiB		481 Bytes	2021-11-4 21:11:19
AC	Elva	11ms	256 KiB		489 Bytes	2021-11-7 9:23:05
AC	殷臣不度	13ms	308 KiB		574 Bytes	2021-11-7 14:52:55
AC	dadazi	17ms	504 KiB		424 Bytes	2022-3-16 22:05:50
AC	albertzm	19ms	420 KiB		481 Bytes	2021-11-5 13:34:38
AC	mibbp	19ms	428 KiB		481 Bytes	2021-11-5 14:14:03
AC	mibbp	19ms	412 KiB		481 Bytes	2021-11-7 10:09:30
AC	mibbp	19ms	432 KiB		481 Bytes	2021-11-7 9:32:56
AC	yunhai	19ms	504 KiB		473 Bytes	2021-11-8 19:16:34
AC	mibbp	19ms	404 KiB		481 Bytes	2021-11-8 19:19:33
AC	yunhai	20ms	376 KiB		473 Bytes	2021-11-8 19:07:50
AC	swpudxf	20ms	412 KiB		473 Bytes	2021-11-8 19:17:09
AC	yunhai	20ms	400 KiB		444 Bytes	2021-11-8 19:05:32
AC	dumpline	21ms	388 KiB		478 Bytes	2021-11-5 20:06:54
AC	supreme	27ms	4.2 MiB	C	745 Bytes	2021-11-9 21:12:30