#include<stdio.h>

long put(long n)
{
 register long t=n,p=1;
 while(n)
 {
  p*=t%10;
  n--;
 }
 return p%10;
}

int main()
{
 freopen("cifra.in","r",stdin);
 freopen("cifra.out","w",stdout);
 int s=0,n;
 register int i;
 long a[30001];
 register long j;
 scanf("%d",&n);
 for(i=1; i<=n; i++)
 {
  s=0;
  scanf("%ld",&a[i]);
  for(j=1; j<=a[i]; j++) s+=put(j);
  printf("%d\n",s%10);
 }
 return 0;
}