#include <bits/stdc++.h>
using namespace std;
using ll = long long;

const ll INF = 1e18;

int n, par[200200], p[200200];
ll a[200200], b[200200], c[200200], d[200200];
vector<int> v[200200];
priority_queue<array<ll, 4>> pq;

void dfs(int u, int p) {
    par[u] = p;
    for(auto x : v[u]) if(x != p) dfs(x, u);
}

int find(int x) {
    if(x == p[x]) return x;
    return p[x] = find(p[x]);
}

int main() {
    cin.tie(0)->sync_with_stdio(0);
    int tc; cin >> tc;
    while(tc--) {
        cin >> n;
        for(int i=1;i<=n;i++) v[i].clear();
        while(!pq.empty()) pq.pop();

        for(int i=2;i<=n;i++) cin >> a[i] >> b[i];
        for(int i=1;i<n;i++) {
            int x, y; cin >> x >> y;
            v[x].push_back(y), v[y].push_back(x);
        }

        dfs(1, 0);
        iota(p+1, p+1+n, 1);

        for(int i=2;i<=n;i++) c[i] = b[i]-a[i], d[i] = -a[i];
        for(int i=2;i<=n;i++) pq.push({c[i]>0, d[i], c[i], i});

        while(!pq.empty()) {
            auto [t, D, C, u] = pq.top(); pq.pop();
            if(D != d[u] || C != c[u]) continue;

            int x = find(par[u]);
            p[u] = x;

            if(D || C) {
                d[x] = min(d[x], c[x]+D), c[x] += C;
                if(x != 1) pq.push({c[x]>0, d[x], c[x], x});
            }
        }

        cout << -d[1] << "\n";
    }
}