#include <iostream>
#include <iomanip>
#include <vector>
#include <string>
#include <set>
#include <queue>
#include <cmath>
#include <algorithm>
#include <bits/stdc++.h>
using namespace std;
#include <atcoder/all>
using namespace atcoder;
#define rep(i,n) for (int i = 0; i < (n); ++i)
#define frep(i,a,b) for (int i = (a); i <= (b); ++i)
#define all(x) (x).begin(),(x).end()
#define bit(n,k) ((n>>k)&1) /*nのk bit目*/
#define debug(x) cout << #x << ": " << x << endl;
typedef long long ll;
using P = pair<ll,ll>;
using P2 = pair<ll,P>;
using mint = modint1000000007;
#define INF 1001001001
#define LINF (1LL<<60)
#define F first
#define S second
template<class T> inline bool chmax(T& a, T b){ if(a<b){ a=b; return 1; } return 0; }
template<class T> inline bool chmin(T& a, T b){ if(a>b){ a=b; return 1; } return 0; }

int n, q;
vector<vector<int>> to;
vector<ll> h;

void dfs(int v, int p = -1) {
  h[v] = 1;
  for (int u : to[v]) {
    if (u == p) continue;
    dfs(u, v);
    h[v] += h[u];
  }
  return;
}

int main() {
  cin >> n >> q;
  to.resize(n);
  rep(i, n-1) {
    int a, b;
    cin >> a >> b;
    to[a-1].push_back(b-1);
    to[b-1].push_back(a-1);
  }
  h.resize(n);
  dfs(0);
  ll ans = 0;
  rep(i, q) {
    ll p, x;
    cin >> p >> x;
    ans += h[p-1] * x;
    cout << ans << endl;
  }
}