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

#define N 102

int main()
{
  char v[N];
  int n, t, s, i, nr;
  int a[10][4] =
  {
    {0,0,0,0},
    {1,1,1,1},
    {6,2,4,8},
    {1,3,9,7},
    {6,4,6,4},
    {5,5,5,5},
    {6,6,6,6},
    {1,7,9,3},
    {6,8,4,2},
    {1,9,1,9}};

  freopen("cifra.in", "r", stdin);
  freopen("cifra.out", "w", stdout);

  scanf("%d", &t);

  for(;t;t--)
  {
    scanf("%s", v);
    n = strlen(v);

    if(n > 1)
      nr = (v[n-2] - '0') * 10 + v[n-1] - '0';
    else
      nr = v[n-1] - '0';

    s = 0;

    for(i = nr - nr%20 + 1; i <= nr; i++)
      s += a[i%10][i%4];

    printf("%d\n", s % 10);
  }
}