#include<bits/stdc++.h>
using namespace std;
using ll = long long;
//using LL = __int128
#define pi pair<ll, ll>
#define fi first
#define se second
#define N 111111
ll t, n, a[N], x, y, d[N];
int main(){
	scanf("%lld", &t);
	while(t--){
		scanf("%lld", &n);
		for(int i = 1 ; i <= n ; i++)
			scanf("%lld", &a[i]);
		memset(d, 0, sizeof d);
		ll ans = (n == 2) * a[1];
		for(int i = 1 ; i < n ; i++){
			scanf("%lld%lld", &x, &y);
			ans = max(ans, a[max(x, y)]);
		}
		printf("%lld", ans);
	}
	return 0;
}
/*
	freopen(".in", "r", stdin);
	freopen(".out", "w", stdout);

*/