#include <stdio.h>
#include <bits/stdc++.h>
#include <atcoder/all>
using namespace atcoder;
using mint = modint998244353;
using namespace std;
#define rep(i,n) for (int i = 0; i < (n); ++i)
#define Inf 1000000001

vector<vector<int>> E;
vector<long long> ans;

void dfs(int cur,int p){
	ans[cur] = 1;
	rep(i,E[cur].size()){
		int to = E[cur][i];
		if(to==p)continue;
		dfs(to,cur);
		ans[cur] += ans[to];
	}
}

int main(){
	
	int n,q;
	cin>>n>>q;
	
	E.resize(n);
	rep(i,n-1){
		int u,v;
		cin>>u>>v;
		u--;v--;
		E[u].push_back(v);
		E[v].push_back(u);
	}
	ans.resize(n,0);
	dfs(0,-1);
	long long A = 0;
	rep(_,q){
		long long p,x;
		cin>>p>>x;
		p--;
		A += x * ans[p];
		cout<<A<<endl;
	}
	
	return 0;
}