#include <algorithm>
#include <bitset>
#include <cassert>
#include <cmath>
#include <cstdio>
#include <fstream>
#include <functional>
#include <iomanip>
#include <iostream>
#include <iterator>
#include <map>
#include <numeric>
#include <queue>
#include <set>
#include <sstream>
#include <stack>
#include <unordered_set>
using namespace std;
#if __has_include(<atcoder/all>)
#include <atcoder/all>
using namespace atcoder;
#endif
#define GET_MACRO(_1, _2, _3, NAME, ...) NAME
#define _rep(i, n) _rep2(i, 0, n)
#define _rep2(i, a, b) for(int i = (int)(a); i < (int)(b); i++)
#define rep(...) GET_MACRO(__VA_ARGS__, _rep2, _rep)(__VA_ARGS__)
#define all(x) (x).begin(), (x).end()
#define rall(x) (x).rbegin(), (x).rend()
using i64 = long long;
template<class T, class U>
bool chmin(T& a, const U& b) { return (b < a) ? (a = b, true) : false; }
template<class T, class U>
bool chmax(T& a, const U& b) { return (b > a) ? (a = b, true) : false; }

template<typename T>istream& operator>>(istream&i,vector<T>&v){rep(j,v.size())i>>v[j];return i;}
template<typename T>string join(vector<T>&v){stringstream s;rep(i,v.size())s<<' '<<v[i];return s.str().substr(1);}
template<typename T>ostream& operator<<(ostream&o,vector<T>&v){if(v.size())o<<join(v);return o;}
template<typename T>string join(vector<vector<T>>&vv){string s="\n";rep(i,vv.size())s+=join(vv[i])+"\n";return s;}
template<typename T>ostream& operator<<(ostream&o,vector<vector<T>>&vv){if(vv.size())o<<join(vv);return o;}

vector<vector<int>> edge;
vector<int> dp;

int dfs(int now, int p){
    int res = 0;
    for (auto i: edge[now]){
        if (i == p) continue;
        res += dfs(i, now);
    }
    return dp[now] = res + 1;
}

int main(){
    cin.tie(nullptr);
    ios::sync_with_stdio(false);
    int n, q;
    cin >> n >> q;
    edge.resize(n);
    dp.resize(n);
    rep(i, n - 1){
        int a, b;
        cin >> a >> b;
        a--, b--;
        edge[a].emplace_back(b);
        edge[b].emplace_back(a);
    }
    dfs(0, -1);
    i64 ans = 0;
    vector<i64> k(q);
    rep(i, q){
        int p, x;
        cin >> p >> x;
        p--;
        ans += dp[p] * x;
        k[i] = ans;
    }
    for (auto i: k) cout << i << "\n";
}