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

int len(int x){//xの桁数
    int rt = 0;
    while(x>0){
        x /= 10;
        rt++;
    }
    return rt;
}

void solve(){
    //Pow2[i] = 2**i, Pow5[i] = 5**i, Pow10[i] = 10**i
    vector<ll> Pow2(11,1),Pow5(11,1),Pow10(11,1);
    for(int i = 1; i <= 10; i++){
        Pow2[i] = Pow2[i-1] * 2;
        Pow5[i] = Pow5[i-1] * 5;
        Pow10[i] = Pow10[i-1] * 10;
    }

    int N; cin >> N;
    vector<ll> A(N);
    for(int i = 0; i < N; i++)cin >> A[i];

    //i=2,3,4,...,N全てについて、A_i * 2**X * 5**Y >= 10^len(A_i)ならそれが答え
    for(int X = 0; X <= 10; X++){
        for(int Y = 0; Y <= 10; Y++){
            bool c = 1;
            for(int i = 0; i < N; i++){
                if(!(A[i] * Pow2[X] * Pow5[Y] % Pow10[len(A[i])] == 0))c = 0;
            }
            if(c){
                cout << Pow2[X] * Pow5[Y] << endl;
                return;
            }
        }
    }
    return;
}

int main(){
    int T; cin >> T;
    for(int testcase = 0; testcase < T; testcase++){
        solve();
    }
    return 0;
}