#include <iostream.h>
#include <fstream.h>
#include <string.h>

/*

 1 ^ 1   ==  1
 2 ^ 2   ==  4
 3 ^ 3   ==  7
 4 ^ 4   ==  6
 5 ^ 5   ==  5
 6 ^ 6   ==  6
 7 ^ 7   ==  3
 8 ^ 8   ==  6
 9 ^ 9   ==  9
10 ^ 10  ==  0
11 ^ 11  ==  1
12 ^ 12  ==  6
13 ^ 13  ==  3
14 ^ 14  ==  6
15 ^ 15  ==  5
16 ^ 16  ==  6
17 ^ 17  ==  7
18 ^ 18  ==  4
19 ^ 19  ==  9
20 ^ 20  ==  0

---------------
            94


*/

int main(void)
{
 fstream f1("cifra.in",ios::in);
 fstream f2("cifra.out",ios::out);
 long a = 0;
 long b = 0;
 char N_[100];
 long N = 0;
 long T = 0;
 long NR = 0;
 long n[] = {1,4,7,6,5,6,3,6,9,0,1,6,3,6,5,6,7,4,9,0};
 f1 >> T;
 for (b = 0;b < T;b = b + 1)
  {
   f1 >> N_;
   N = N_[strlen(N_) - 1];
   NR = (4 * (N / 20)) % 10;
   for (a = 0;a < (N % 20);a = a + 1)
    {
     NR = NR + n[a];
    }
   f2 << (NR % 10) << endl;
  }
 f1.close();
 f2.close();
 return 0;
}