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

// 1^1 + ... + 1^20 ends in 4, and it's all periodic from there.

int a[4][10] = {{1, 2, 3, 4, 5, 6, 7, 8, 9, 0},
		{1, 4, 9, 6, 5, 6, 9, 4, 1, 0},
		{1, 8, 7, 4, 5, 6, 3, 2, 9, 0},
		{1, 6, 1, 6, 5, 6, 1, 6, 1, 0}};
FILE *fin, *fout;

void query(char* s) {
  int l = strlen(s);
  s[--l] = 0; // discard the \n
  l -= 2;
  if (l < 0) {
    l = 0;
  }
  int n = atoi(s + l);
  int result = (n / 20) * 4;
  n %= 20;
  for (int i = 0; i < n; i++) {
    result += a[i % 4][i % 10];
  }
  fprintf(fout, "%d\n", result % 10);
}

int main(void) {
  int numTests;
  fin = fopen("cifra.in", "rt");
  fout = fopen("cifra.out", "wt");
  fscanf(fin, "%d\n", &numTests);
  char s[200];
  for (int testNum = 0; testNum < numTests; testNum++) {
    fgets(s, 150, fin);
    query(s);
  }

  fclose(fin);
  fclose(fout);
  return 0;
}