#include <stdio.h>

int v[100], s[100];

int main()
{
    FILE *fin, *fout;
    int t, j, nr, i, p, k;
    char a, b, c;

    fin = fopen ( "cifra.in", "r" );
    fout = fopen ( "cifra.out", "w" );
    fscanf ( fin, "%d\n", &t );

    for ( i = 1; i < 20; i++ ) {
        p = 1;
        for ( j = 1; j <= i; j++ )
            p = p * i % 10;
        v[i] = p;
    }
    for ( i = 20; i < 100; i++ )
        v[i] = v[i-20];
    for ( i = 1; i < 100; i++ )
        s[i] = ( s[i-1] + v[i] ) % 10;

    for ( i = 0; i <= t - 1; i++ ) {
        while ( nr > 10 ) {
          k = k + 9;
          nr = nr - 10;
        }
        v[i] = k;
      }
    for ( j = 1; j <= t; j++ ) {
      k = 0;
      c = fgetc ( fin );
      b = c;
      c = fgetc ( fin );
      a = 0;
      while ( c != '\n' ) {
        a = b;
        b = c;
        c = fgetc ( fin );
      }
      if (a != 0)
        nr = (a - '0') * 10 + b - '0';
      else
        nr = b - '0';
      fprintf( fout, "%d\n", s[nr] );

    }

    fclose ( fin );
    fclose ( fout );

    return 0;
}