#include <bits/stdc++.h>
using namespace std;
#define int long long
#define pii pair<int,int>
const int mxn = 100005;
vector<vector<int>>adj(mxn);
vector<int>dp(mxn);
vector<int>sum(mxn);
vector<int>a(mxn);
vector<int>b(mxn);
bool comp(pii a, pii b){
	return max(a.first, a.second + b.first) < max(b.first, b.second + a.first);
}
void dfs(int u, int p){
	vector<pii>vals;
	sum[u] = b[u]-a[u];
	for(int nxt: adj[u]){
		if(nxt==p)continue;
		dfs(nxt,u);
		sum[u]+=sum[nxt];
		vals.push_back({dp[nxt],sum[nxt]});
	}
	sort(vals.begin(),vals.end(),comp);
	int rq = a[u];
	int cur = a[u]-b[u];
	for(auto [x,y] : vals){
		cur+=x;
		rq = max(rq,cur);
		cur-=x;
		cur-=y;
	}
	dp[u] = rq;
}
void reset(int n){
	for(int i = 1; i<=n; i++){
		adj[i].clear();
		dp[i] = sum[i] = a[i] = b[i] = 0;
	}
}
signed main(){
	cin.tie(nullptr)->sync_with_stdio(false);
	int t;
	cin >> t;
	while(t--){
		int n;
		cin >> n;
		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;
			adj[x].push_back(y);
			adj[y].push_back(x);
		}
		
		dfs(1,0);
		cout << dp[1] << '\n';
		reset(n);
	}
	return 0;
}