#include <bits/stdc++.h>
#define int long long
#define endl "\n"
using namespace std;


int binpow(int a,int p)
{
  if (p==0) return 1;
  if (p%2) return binpow(a,p-1)*a;
  int t = binpow(a,p/2);
  return t*t;
}


void solve()
{
  int n;cin>>n;
  vector<int> arr;
  for (int i = 0; i < n; i++)
  {
    int t;cin>>t;
    arr.push_back(t);
  }
  
  int max2 = 0;
  int max5 = 0;
  
  for (int i = 1; i < n; i++)
  {
    int curr2 = 0;
    int curr5 = 0;
    int tempcurr = arr[i];
    // cout << arr[i] << " " << (tempcurr%2==0) << " " << tempcurr << endl;
    while (tempcurr!=0 && tempcurr%2==0)
    {
      curr2++;
      tempcurr/=2;
    }
    tempcurr = arr[i];
    while (tempcurr !=0 && tempcurr%5==0)
    {
      curr5++;
      tempcurr/=5;
    }
    int len = 0;
    tempcurr = arr[i];
    while (tempcurr)
    {
      len++;
      tempcurr/=10;
    }
  
    max2 = max(max2, max(len-curr2, 0ll));
    max5 = max(max5, max(len-curr5, 0ll));
        // cout << arr[i] << " " << curr2 << " " << curr5 << " " << len << endl;

  }
  
  cout << binpow(2,max2)*binpow(5,max5) << endl;
}

signed main() 
{
  ios_base::sync_with_stdio(0);
  cin.tie(0);
  
  int t;cin>>t;while(t--)
  solve();
}