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

int main ()
{
  int a[]={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 num[101];
  fscanf(in, "%d", &T);
  while(T--)
  {
  	fscanf(in, "%s", num);
    n = strlen(num);
	k=(n<=1?0:(num[n-2]-'0'));
	fprintf(out, "%d\n", (k*7+a[10*(k%2)+(num[n-1]-'0')])%10);
  }
  return 0;
}