#include <iostream>
#include <string>
#include <vector>
#include <algorithm>
#include <utility>
#include <map>
#include <cmath>
using namespace std;
typedef long long ll;
#define rep(i, n) for (int i=0;i < (int)(n);i++)

vector<vector<int>> g;
vector<int> subsize;

int dfs(int now,int pre){
    int res = 1;
    for (auto nx:g[now]){
        if (nx == pre) continue;
        res += dfs(nx,now);
    }
    return subsize[now] = res;
}

int main(){
    int n,q;
    cin >> n >> q;
    g.resize(n);
    subsize.resize(n);
    rep(i,n-1){
        int a,b;
        cin >> a >> b;
        a--;b--;
        g[a].push_back(b);
        g[b].push_back(a);
    }
    ll ans = 0;
    dfs(0,-1);
    while(q--){
        int p;
        ll x;
        cin >> p >> x;
        ans += subsize[p-1] * x;
        cout << ans << endl;
    }
    return 0;
}