#include <bits/stdc++.h>
#define all(x) (x).begin(), (x).end()
using namespace std;
typedef long long ll;
typedef pair<ll, ll> pii;
typedef pair<ll, pii> pip;
#define MAXN (ll)(4e5 + 5)
const ll mod = (ll)(1e9 + 7);

ll a[MAXN], b[MAXN];
vector<int> g[MAXN];
ll dp[MAXN], best[MAXN], fin[MAXN];

void dfs(int u, int p) {
	vector<pip> sons;
	ll minimal_fin_v = 1e18;
	ll summm = b[u] - a[u];
	for (auto v : g[u]) {
		if (v == p)
			continue;
		dfs(v, u);
		minimal_fin_v = min(minimal_fin_v, fin[v]);
		sons.push_back(pip(dp[v], pii(best[v] - dp[v], best[v] - fin[v])));
		summm += (fin[v] - dp[v]);
	}
	dp[u] = a[u];
	best[u] = max(a[u], b[u]);
	fin[u] = b[u];
	if (sons.empty()) {
		// cout << u << ' ' << dp[u] << ' ' << best[u] << ' ' << fin[u] << "\n";
		return;
	}
	ll act = b[u];
	sort(all(sons));
	ll res = 0;
	for (auto p : sons) {
		ll mi = p.first;
		ll add = p.second.first;
		ll men = p.second.second;
		res += men;
		if (mi > act) {
			dp[u] += mi - act;
			act = mi;
		}
		act += add;
	}
	if (minimal_fin_v + res > act) {
		dp[u] += minimal_fin_v + res - act;
		act = minimal_fin_v + res;
	}
	best[u] = max(best[u], act);
	fin[u] = dp[u] + summm;
	// cout << u << ' ' << dp[u] << ' ' << best[u] << ' ' << fin[u] << "\n";
}

int32_t main() {
	ios_base::sync_with_stdio(0);
	cin.tie(0);

	int t;
	cin >> t;
	while (t--) {
		int n;
		cin >> n;
		for (int i = 1; i < n; i++)
			cin >> a[i] >> b[i];
		for (int i = 0; i < n - 1; i++) {
			int u, v;
			cin >> u >> v;
			u--, v--;
			g[u].push_back(v);
			g[v].push_back(u);
		}

		dfs(0, -1);

		cout << dp[0] << "\n";

		for (int i = 0; i < n; i++) {
			a[i] = b[i] = 0;
			dp[i] = best[i] = fin[i] = 0;
			g[i].clear();
		}
	}

	return 0;
}