#include<bits/stdc++.h>
using namespace std;
using ll = long long;
using pint = pair<int, int>;
using pll = pair<ll, ll>;

void dfs(int v, int p, vector<vector<int>> &G, vector<ll> &sz){
    if(p != -1 && G[v].size() == 1){
        sz[v] = 1;
        return;
    }
    int sum = 0;
    for(int nv: G[v]){
        if(nv == p)continue;
        dfs(nv, v, G, sz);
        sum += sz[nv];
    }
    sz[v] = ++sum;
}

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<pll> q(Q);
    for(int i = 0; i < Q; i++){
        ll p, x; cin >> p >> x;
        --p; q[i] = {p, x};
    }
    vector<ll> sz(N);
    dfs(0, -1, G, sz);
    ll tot = 0;
    for(int i = 0; i < Q; i++){
        ll p, x; tie(p, x) = q[i];
        tot += sz[p] * x;
        cout << tot << endl;
    }
}