#include <iostream>

using namespace std;

int main()
{
   int n;

   cout << "Enter n";
   cin >> n;

   int arr[n];

   for (int i = 0; i < n; i++){
        cin >> arr[i];
   }
    cout << "\n";
   for (int i = 1; i < n; i *= 5) {
        cout << arr[i];
   }

   return 0;
}