print(eval(input().replace("(", "**(")))

#include<bits/stdc++.h>
using namespace std;
#define _rep(i, a, n) for(int i = a; i < n; i++)
const int maxn = 100010;
int a[maxn], aa[maxn], res[maxn];
int main(){
	int t, tmp;
	cin >> t;
	while(t--){
		int cnt = 0;
		int n;
		cin >> n;
		_rep(i, 0, n){
			cin >> tmp;
			if(tmp == 0) cnt++;
			else{
				a[i - cnt] = tmp;
			}
		}
		sort(a, a + n - cnt);
		int top = n - 2;
		int bb = a[0];
		aa[n - 1] = 0;
		aa[top--] = a[1];
		_rep(i, 0, cnt) aa[top--] = 0;
		_rep(i, 2, n - cnt){
			aa[top--] =a[i];
		}
		_rep(i, 0, n){
			tmp = bb * aa[i] + res[i];
			if(tmp > 9){
				aa[i] = tmp % 10;
				res[i+1] += tmp / 10;
			}
			else aa[i] = tmp;
		}
		if(aa[n - 1] > 0) printf("%d", aa[n-1]);
		res[n-1] = 0;
		for(int i = n - 2; i >= 0; i--) printf("%d", aa[i]), res[i] = 0;
		cout << endl;
	}
}