ll@N,@P[N],Q[N+1]{},R[]{},S[]{};rep(i,N)Q[P[i]]=1;rep(i,N)R[Q[i+1]?0:P[i]]=1;rep(i,N)S[R[i+1]*P[i]]=1;wt(sum[i,1,N+1](S[i]));