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

int main ()
{
  int magic1[]={0, 1, 5, 2, 8, 3, 9, 2, 8, 7}, magic2[]={0, 1, 7, 0, 6, 1, 7, 4, 1, 0}, T;
  FILE *in=fopen("cifra.in", "r"), *out=fopen("cifra.out", "w");
  char number[101];
  fscanf(in, "%d", &T);
  while(T--)
  {
  	fscanf(in, "%s", number);
  	int n = strlen(number);
	int k1=(number[n-1]-'0'), k2=(n<=1?0:(number[n-2]-'0'));
	fprintf(out, "%d\n", (k2*7+ (k2%2?magic2[k1]:magic1[k1]))%10 );
  }
  fclose(in);
  fclose(out);
  return 0;
}