i tried to solve this problem but i have WA 19 , many trials without result so i hope some one can help me <3

my solutin idea :

for each u  we preprocess it that we store for it the 1<<k elemnt after  u in valid sequence    dp[u][k]  and sum untill this elemnt   sum[u][k]  >>  so we can ans queryies about u in log time [submission:268374991]