#include <iostream>
#include <vector>
#include "testlib.h"
using namespace std;

struct Edge {
    int u;
    int v;
    int cost;
    Edge(int a, int b, int c) : u(a), v(b), cost(c) {

    }
};
using Graph = vector<vector<Edge>>;

vector<int> depth;
vector<long long> subtree_size;
vector<bool> seen;
void dfs(const Graph& G, int v, int p, int d) {
    depth[v] = d;
    seen[v] = true;
    for (auto nv : G[v]) {
        if (nv.v == p) continue;
        dfs(G, nv.v, v, d + 1);
    }

    subtree_size[v] = 1;
    for (auto c : G[v]) {
        if (c.v == p) continue;
        subtree_size[v] += subtree_size[c.v];
    }
}

int main() {
    registerValidation();
    long long N = inf.readInt(2, 100000, "N");
    inf.readSpace();
    long long Q = inf.readInt(1, 100000, "Q");
    inf.readEoln();

    Graph G(N);
    for (int i = 0; i < N - 1; i++) {
        int a = inf.readInt(1, N, "a");
        inf.readSpace();
        int b = inf.readInt(1, N, "b");
        inf.readEoln();
        G[a - 1].emplace_back(a - 1, b - 1, 1);
        G[b - 1].emplace_back(b - 1, a - 1, 1);
    }

    depth.assign(N, 0);
    subtree_size.assign(N, 0);
    seen.assign(N, false);

    dfs(G, 0, -1, 0);

    for (int i = 0; i < N; i++) {
        if (seen[i] == false) cout << -1 << endl;
    }

    long long ans = 0;
    for (int i = 0; i < Q; i++) {
        long long p = inf.readInt(1, N, "p");
        inf.readSpace();
        long long x = inf.readInt(1, 100000000, "x");
        inf.readEoln();
        ans += subtree_size[p - 1] * x;
        cout << ans << endl;
    }
    inf.readEof();
}