你是MLE+TLE
建议用结构体存FHQTreap
然后```kth```函数部分```while(1)```改成```while(now)```
只是建议，蒟蒻比较菜
by AoPSer @ 2023-10-20 21:58:31
然后case2 写错了，第二行是(x,a-1,x,z)
by AoPSer @ 2023-10-20 22:05:35
https://www.luogu.com.cn/record/130679840
by AoPSer @ 2023-10-20 22:06:23