#include <cstdio>
#include <string.h>

int main ()
{
  int magic[]={0, 1, 5, 2, 8, 3, 9, 2, 8, 7, 0, 1, 7, 0, 6, 1, 7, 4, 8, 7}, T, n, k;
  FILE *in=fopen("cifra.in", "r"), *out=fopen("cifra.out", "w");
  char nbr[101];
  fscanf(in, "%d", &T);
  while(T--)
  {
  	fscanf(in, "%s", nbr);
    n = strlen(nbr);
	k=(n<=1?0:(nbr[n-2]-'0'));
	fprintf(out, "%d\n", (k*7+magic[10*(k%2)+(nbr[n-1]-'0')])%10);
  }
  return 0;
}