#line 1 "/workspaces/compro/lib/template.hpp"


#line 1 "/workspaces/compro/lib/io/vector.hpp"
#include <iostream>
#include <vector>

#ifndef IO_VECTOR
#define IO_VECTOR

template <class T> std::ostream &operator<<(std::ostream &out, const std::vector<T> &v) {
  int size = v.size();
  for (int i = 0; i < size; i++) {
    std::cout << v[i];
    if (i != size - 1)
      std::cout << " ";
  }
  return out;
}

template <class T> std::istream &operator>>(std::istream &in, std::vector<T> &v) {
  for (auto &el : v) {
    std::cin >> el;
  }
  return in;
}

#endif
#line 4 "/workspaces/compro/lib/template.hpp"
#include <bits/stdc++.h>
#define REP(i, n) for (int i = 0; i < n; i++)
#define FOR(i, m, n) for (int i = m; i < n; i++)
#define ALL(v) (v).begin(), (v).end()
#define coutd(n) cout << fixed << setprecision(n)
#define ll long long int
#define vl vector<ll>
#define vi vector<int>
#define MM << " " <<

using namespace std;

template <class T> void chmin(T &a, T b) {
  if (a > b)
    a = b;
}

template <class T> void chmax(T &a, T b) {
  if (a < b)
    a = b;
}

// 重複を消す。計算量はO(NlogN)
template <class T> void unique(std::vector<T> &v) {
  std::sort(v.begin(), v.end());
  v.erase(std::unique(v.begin(), v.end()), v.end());
}


#line 2 "main.cpp"

void solve(int N, int Q, const std::vector<long long> &a, const std::vector<long long> &b,
           const std::vector<long long> &p, const std::vector<long long> &x) {
  vector<vector<int>> g(N);
  REP(i, N - 1) {
    g[a[i]].push_back(b[i]);
    g[b[i]].push_back(a[i]);
  }

  vl size(N, 0);
  auto dfs = [&](int cur, int par, auto self) -> void {
    size[cur] = 1;
    for (const auto &el : g[cur]) {
      if (el == par)
        continue;
      self(el, cur, self);
      size[cur] += size[el];
    }
  };
  dfs(0, -1, dfs);

  ll ans = 0;
  REP(i, Q) {
    ans += size[p[i]] * x[i];
    cout << ans << endl;
  }
}

// generated by online-judge-template-generator v4.7.1 (https://github.com/online-judge-tools/template-generator)
int main() {
  ios::sync_with_stdio(false);
  cin.tie(nullptr);
  int N, Q;
  std::cin >> N;
  std::vector<long long> a(N - 1), b(N - 1);
  std::cin >> Q;
  std::vector<long long> p(Q), x(Q);
  for (int i = 0; i < N - 1; ++i) {
    std::cin >> a[i] >> b[i];
    a[i]--;
    b[i]--;
  }
  for (int i = 0; i < Q; ++i) {
    std::cin >> p[i] >> x[i];
    p[i]--;
  }
  solve(N, Q, a, b, p, x);
  return 0;
}