typedef long long ll;
typedef long double ld;
#include <bits/stdc++.h>
using namespace std;
#define int long long

signed main(){
    ll n,q;
    std::cin >> n>>q;
    vector<vector<ll>> edges(n);
    for (int i = 0; i < n-1; i++) {
        ll a,b;
        std::cin >> a>>b;
        a--;b--;
        edges[a].push_back(b);
        edges[b].push_back(a);
    }
    vector<ll> size(n);
    function<ll(ll,ll)> dfs = [&](ll now, ll par){
        ll sum = 1;
        for (auto e : edges[now]) {
            if(e==par)continue;
            sum += dfs(e, now);
        }
        return size[now] = sum;
    };
    dfs(0,-1);
    ll ans = 0;
    for (int i = 0; i < q; i++) {
        ll p,x;
        std::cin >> p>>x;
        p--;
        ans += x*size[p];
        std::cout << ans << std::endl;
    }
}