[qwq](http://usaco.org/current/data/sol_prob3_gold_open21.html)
by cmll02 @ 2021-04-12 11:52:50
@[cmll02](/user/171487) [我的题解](https://blog-e.tk/2021/04/03/USACO-2021-US-Open-%E9%87%91%E7%BB%84%E9%A2%98%E8%A7%A3/#t3-permutation) 不知道说的清楚不清楚一点（
by ethan_zhou @ 2021-04-12 12:01:19
@[ethan_zhou](/user/124740) ok,thx
by cmll02 @ 2021-04-12 12:11:52