#include <iostream>
#include <string>
#include <algorithm>
#include <vector>
#include <iomanip>
#include <cmath>
#include <stdio.h>
#include <queue>
#include <deque>
#include <cstdio>
#include <set>
#include <map>
#include <bitset>
#include <stack>
#include <cctype>
using namespace std;
vector<vector<int>> vec(200020);
vector<pair<int,int>> v;
int co[200020] = {};
long long sum[200020] = {};
bool bo[200020] = { false };
int main() {
	long long n, q;
	cin >> n >> q;
	for (int i = 1; i < n; i++) {
		int a, b;
		cin >> a >> b;
		vec[a].emplace_back(b);
		vec[b].emplace_back(a);
		co[a]++, co[b]++;
		sum[i] = 1;
	}
	sum[n] = 1;
	bo[1] = true;
	queue<int> que;
	que.push(1);
	while (!que.empty()) {
		int x = que.front();
		que.pop();
		for (int i = 0; i < vec[x].size(); i++) {
			if (!bo[vec[x][i]]) {
				bo[vec[x][i]] = true;
				que.push(vec[x][i]);
				v.emplace_back(make_pair(vec[x][i], x));
			}
		}
	}
	reverse(v.begin(), v.end());
	for (int i = 0; i < v.size(); i++) {
		sum[v[i].second] += sum[v[i].first];
	}
	long long ans = 0;
	for (int i = 0; i < q; i++) {
		int p;
		long long x;
		cin >> p >> x;
		ans += sum[p] * x;
		cout << ans << endl;
	}
}