#include <bits/stdc++.h>
using namespace std;
#if __has_include(<atcoder/all>)
#include <atcoder/all>
using namespace atcoder;
using mint = modint998244353;
#endif
using ll = long long;
using ld = long double;
const ll INF = 1ll<<60;
const ld EPS = 1.0/1e9;
#define endl "\n"
#define rep(i,a,b) for(int i=a;i<b;i++)
#define rrep(i,a,b) for(int i=a;i>=b;i--)
#define fore(i,a) for(auto &i:a)
#define all(x) (x).begin(),(x).end()
#define del(x) sort(all(x)); x.erase(unique(all(x)),x.end());
vector<ll>x(101010,1);
void dfs(vector<vector<ll>>& G,int s,int p){
  fore(c,G[s]) if(c!=p){
    dfs(G,c,s);
    x[s]+=x[c];
  }
  return;
}

int main(){
  ios_base::sync_with_stdio(0);
  cin.tie(0);
  ll n,q; cin >> n >> q;
  vector<vector<ll>>G(n);
  rep(i,0,n-1){
    ll a,b; cin >> a >> b;
    a--; b--;
    G[a].push_back(b);
    G[b].push_back(a);
  }
  dfs(G,0,-1);
  ll ans=0;
  rep(i,0,q){
    ll p,s; cin >> p >> s;
    p--; 
    ans+=x[p]*s;
    cout << ans << endl;
  }
}