#include <bits/stdc++.h>
using namespace std;
int main(){
    int N, Q;
    cin >> N >> Q;
    vector<vector<int>> G(N);
    for(int i = 0; i < N - 1; i++){
        int a, b;
        cin >> a >> b;
        a--;
        b--;
        G[a].push_back(b);
        G[b].push_back(a);
    }
    vector<long long> cnt(N);
    auto dfs = [&](auto dfs, int now, int par) -> void{
        for(int t: G[now]){
            if(t == par) continue;
            dfs(dfs, t, now);
            cnt[now] += cnt[t];
        }
        cnt[now]++;
    };
    dfs(dfs, 0, -1);
    long long ans = 0;
    while(Q--){
        int p;
        cin >> p;
        long long x;
        cin >> x;
        p--;
        ans += cnt[p] * x;
        cout << ans << endl;
    }
}