#include <stdio.h>
#include <string.h>

int main() {
  FILE *fi, *fo;
  short uc[2][10] = {{1, 4, 7, 6, 5, 6, 3, 6, 9, 0},
		     {1, 6, 3, 6, 5, 6, 7, 4, 9, 0}};
  int t, i, l, ultn, rest,j, p, pen;
  char n[102];
  fi = fopen("cifra.in", "r");
  fo = fopen("cifra.out", "w");
  fscanf(fi, "%d", &t);
  for (i = 0; i < t; i++) {
    fscanf(fi, "%s", n);
    ultn = 0;
    p = 0;
    l = strlen(n);
    if (l > 1) {
      pen = n[l-2] - '0';
      ultn = pen * 7;
      p = pen % 2;
    }
    rest = n[l-1] - '0';

    for (j = 0; j < rest; j++) {
      ultn += uc[p][j];
    }
    ultn = ultn % 10;
    fprintf(fo, "%d\n", ultn);
  }
  fclose(fi);
  fclose(fo);
  return 0;
}