#include <bits/stdc++.h>
using namespace std;

vector<vector<int>> g;
vector<int> d;

int dfs( int v, int p )
{
	int res = 0;
	for( int x : g[v] ) {
		if( x == p ) continue;
		res += dfs( x, v ) + 1;
	}
	d[v] = res + 1;
	return res;
}

int main()
{
	int N, Q;
	cin >> N >> Q;
	g = vector<vector<int>>( N );
	d = vector<int>( 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 );
	}

	dfs( 0, -1 );
	long long ans = 0;
	for( int i = 0; i < Q; i++ ) {
		int p;
		long long x;
		cin >> p >> x;
		p--;
		ans += d[p] * x;
		cout << ans << endl;
	}
}