#include <bits/stdc++.h>
#define REP(i, n) for (int i = 0; (i) < (int)(n); ++(i))
#define REP3(i, m, n) for (int i = (m); (i) < (int)(n); ++(i))
#define REP_R(i, n) for (int i = (int)(n)-1; (i) >= 0; --(i))
#define REP3R(i, m, n) for (int i = (int)(n)-1; (i) >= (int)(m); --(i))
#define ALL(x) ::std::begin(x), ::std::end(x)
using namespace std;

vector<int64_t> solve(int n, int q, const std::vector<int> &a, const std::vector<int> &b, const std::vector<int> &p, const std::vector<int64_t> &x) {
    vector<vector<int>> g(n);
    REP (i, n - 1) {
        g[a[i]].push_back(b[i]);
        g[b[i]].push_back(a[i]);
    }
    vector<int> cnt(n);
    auto go = [&](auto &&go, int x, int parent) -> void {
        cnt[x] += 1;
        for (int y : g[x]) if (y != parent) {
            go(go, y, x);
            cnt[x] += cnt[y];
        }
    };
    go(go, 0, -1);
    int64_t cur = 0;
    vector<int64_t> ans(q);
    REP (i, q) {
        cur += cnt[p[i]] * x[i];
        ans[i] = cur;
    }
    return ans;
}

// generated by oj-template v4.8.0 (https://github.com/online-judge-tools/template-generator)
int main() {
    std::ios::sync_with_stdio(false);
    std::cin.tie(nullptr);
    int N, Q;
    std::cin >> N;
    std::vector<int> a(N - 1), b(N - 1);
    std::cin >> Q;
    std::vector<int> p(Q);
    std::vector<int64_t> x(Q);
    REP (i, N - 1) { std::cin >> a[i] >> b[i]; -- a[i]; -- b[i]; }
    REP (i, Q) { std::cin >> p[i] >> x[i]; -- p[i]; }
    auto c = solve(N, Q, a, b, p, x);
    REP (i, Q) { std::cout << c[i] << '\n'; }
    return 0;
}