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

using graph = vector<vector<int>>;

void dfs(const graph &to, vector<int64_t> &children, int v, int p)
{
    children.at(v)++;
    for (auto &&c : to.at(v))
    {
        if (c == p)
        {
            continue;
        }
        dfs(to, children, c, v);
        children.at(v) += children.at(c);
    }
}

int main()
{
    int n, q;
    cin >> n >> q;
    graph to(n);
    for (int i = 0; i < n - 1; i++)
    {
        int a, b;
        cin >> a >> b;
        a--;
        b--;
        to.at(a).push_back(b);
        to.at(b).push_back(a);
    }
    vector<int64_t> children(n);
    dfs(to, children, 0, -1);
    int64_t cost = 0;
    for (int i = 0; i < q; i++)
    {
        int p, x;
        cin >> p >> x;
        p--;
        cost += x * children.at(p);
        cout << cost << endl;
    }
    return 0;
}