#include <bits/stdc++.h>
#include <atcoder/modint>
using namespace std;
using namespace atcoder;
//#pragma GCC optimize("Ofast")
#define reps(i,s,n) for(int i = s; i < n; i++)
#define rep(i,n) reps(i,0,n)
#define Rreps(i,n,e) for(int i = n - 1; i >= e; --i)
#define Rrep(i,n) Rreps(i,n,0)
#define ALL(a) a.begin(), a.end()

using ll = long long;
using vec = vector<ll>;
using mat = vector<vec>;

ll N,M,H,W,Q,K,A,B;
string S;
using P = pair<ll, ll>;
using tp = tuple<ll, ll, ll>;
const ll INF = (1LL<<60);

template<class T> bool chmin(T &a, const T b){
    if(a > b) {a = b; return true;}
    else return false;
}
template<class T> bool chmax(T &a, const T b){
    if(a < b) {a = b; return true;}
    else return false;
}
template<class T> void my_printv(std::vector<T> v,bool endline = true){
    if(!v.empty()){
        for(std::size_t i{}; i<v.size()-1; ++i) std::cout<<v[i]<<" ";
        std::cout<<v.back();
    }
    if(endline) std::cout<<std::endl;
}

int main() {
    cin.tie(nullptr);
    ios::sync_with_stdio(false);
    cin>>N>>Q;
    mat G(N);
    vec subsz(N, 0);
    rep(i, N - 1){
        int a, b;
        cin>>a>>b;
        --a; --b;
        G[a].push_back(b);
        G[b].push_back(a);
    }
    auto dfs = [&](auto &&self, int p, int v) -> int{
        subsz[v] = 1;
        for(int to : G[v]) if(to != p) subsz[v] += self(self, v, to);
        return subsz[v];
    };
    dfs(dfs, -1, 0);
    ll res{};
    while(Q--){
        ll p, x;
        cin>>p>>x;
        res += subsz[p - 1] * x;
        cout<<res<<endl;
    }
}