//#include <atcoder/all>
#include <bits/stdc++.h>
#include <cmath>
using namespace std;
//using namespace atcoder;
using ll = long long;
#define all(A) A.begin(),A.end()
using vll = vector<ll>;
#define rep(i, n) for (long long i = 0; i < (long long)(n); i++)
using Graph = vector<vector<ll>>;
Graph G;
vll E;
vector<bool> seen;
ll k = 0;
void dfs(int v) {
	seen[v] = true; // v を訪問済にする

	// v から行ける各頂点 next_v について
	E[v] = k;
	for (auto next_v : G[v]) {
		if (seen[next_v]) continue; // next_v が探索済だったらスルー
		k++;
		dfs(next_v); // 再帰的に探索
	}
	E[v] = k - E[v];
}

int main() {


	ll N, Q;
	cin >> N >> Q;
	G.assign(N, {});
	seen.assign(N, false);
	vll e(N, 0);
	E.assign(N, 0);
	rep(i, N - 1) {
		ll A, B;
		cin >> A >> B;
		A--; B--;
		G[A].push_back(B);
		G[B].push_back(A);
	}
	dfs(0);
	ll S = 0;
	
	rep(i, Q) {
		ll P, Q;
		cin >> P >> Q;
		S += (E[P - 1]+1) * Q;
		cout << S << endl;
	}
}