#include <bits/stdc++.h>
using namespace std;
#define overload3(_1, _2, _3, name, ...) name
#define rep1(n) for (decltype(n) _tmp = 0; _tmp < n; _tmp++)
#define rep2(i, n) for (decltype(n) i = 0; i < n; i++)
#define rep3(i, a, b) for (decltype(n) i = a; i < b; i++)
#define rep(...) overload3(__VA_ARGS__, rep3, rep2, rep1)(__VA_ARGS__)
struct IOSetup {
    IOSetup() noexcept {
        ios::sync_with_stdio(false);
        cin.tie(nullptr);
        cout << fixed << setprecision(10);
        cerr << fixed << setprecision(10);
    }
} iosetup;
template<class T> bool chmax(T &a, const T &b) { return a < b ? a = b, true : false; }
template<class T> bool chmin(T &a, const T &b) { return a > b ? a = b, true : false; }
using i64 = long long;
using u64 = unsigned long long;

#include <boost/hana/functional/fix.hpp>

#if __has_include(<debug.hpp>)
    #include <debug.hpp>
#else
    #define dbg(...) (void(0))
#endif

int main() {
    size_t n, q;
    cin >> n >> q;
    vector<vector<size_t>> tree(n, vector<size_t>{});
    rep(n - 1) {
        size_t u, v;
        cin >> u >> v;
        tree[u - 1].push_back(v - 1);
        tree[v - 1].push_back(u - 1);
    }
    vector<int> children(n, -1); // inclusive
    boost::hana::fix([&](auto &&dfs, size_t v, size_t prev) -> void {
        int cnt = 1;
        for (const auto &u: tree[v]) {
            if (u == prev) continue;
            if (children[u] == -1) dfs(u, v);
            cnt += children[u];
        }
        children[v] = cnt;
        dbg(v);
    })(0, 0);
    dbg(children);
    i64 ans = 0;
    while (q--) {
        size_t p;
        i64 x;
        cin >> p >> x;
        ans += children[p - 1] * x;
        cout << ans << "\n";
    }
}