#include <bits/stdc++.h>
using namespace std;
#define rep(i,n) for(int i=0; i<(n); i++)
#define INF ((1LL<<62)-(1LL<<31))
#define all(a)  (a).begin(),(a).end()
#define rall(a)  (a).rbegin(),(a).rend()
typedef long long ll;
typedef pair<ll,ll> pl;
typedef tuple<ll,ll,ll> tupl;

int main()
{
    int n,q;
    cin >> n >> q;
    vector<vector<int>> G(n,vector<int> ());
    vector<int> cnt(n,1);
    rep(i,n-1) {
        int a,b;
        cin >> a >> b;
        a--; b--;
        G[a].push_back(b);
        G[b].push_back(a);
    }
    queue<int> qu;
    qu.push(0);
    vector<ll> dist(n,INF);
    vector<int> u;
    dist[0]=0;
    while(!qu.empty()) {
        int v=qu.front();
        qu.pop();
        u.push_back(v);
        for(auto nv:G[v]) {
            if(dist[nv]!=INF) continue;
            dist[nv]=dist[v]+1;
            qu.push(nv);
        }
    }
    reverse(all(u));
    for(auto nu:u) {
        for(auto x:G[nu]) {
            if(dist[x]==dist[nu]-1) cnt[x]+=cnt[nu];
        }
    }
    ll sum=0;
    rep(i,q) {
        ll p,x;
        cin >> p >> x;
        p--;
        sum+=cnt[p]*x;
        cout << sum << endl;
    }
    return 0;
}