#include <bits/stdc++.h>
#define rep(i,n) for(int i=0;i<(int)(n);i++)
#define chmin(x,y) x = min((x),(y))
#define chmax(x,y) x = max((x),(y))
#define popcount(x) __builtin_popcount(x)
using namespace std;
using ll = long long ;
using P = pair<int,int> ;
using pll = pair<long long,long long>;
const int INF = 1e9;
const long long LINF = 1e17;
const int MOD = 1000000007;
//const int MOD = 998244353;
const double PI = 3.14159265358979323846;

int main(){
    int n,q;
    cin >> n >> q;
    vector<vector<int>> tree(n);
    rep(i,n-1){
        int a,b;
        cin >> a >> b;
        --a;--b;
        tree[a].push_back(b);
        tree[b].push_back(a);
    }

    vector<int> sz(n,0);
    auto dfs = [&](auto&& dfs,int i,int p) -> int {
        sz[i] = 1;
        for(int j:tree[i]){
            if(j == p) continue;
            sz[i] += dfs(dfs,j,i);
        }
        return sz[i];
    };
    dfs(dfs,0,-1);

    ll ans = 0;
    for(int i=0;i<q;i++){
        ll p;
        ll x;
        cin >> p >> x;
        --p;
        ans += x * sz[p];
        cout << ans << endl;
    }

    return 0;
}