#include<stdio.h>

FILE*f=fopen("cifra.in","r"),*g=fopen("cifra.out","w");
int t,q;
long n,h;

int cifra2(long h)
{int j=1;
long i;
  for(i=1;i<=h;i++)
   j=(j*(h%10))%10;

return j;
}

int cifra(long n)
{int s=0;
 long i;
 for(i=1;i<=n;i++)
   s=(s+cifra2(i))%10;

  return s;
}

int main()
{
  fscanf(f,"%i",&t);

for(q=1;q<=t;q++)
  { fscanf(f,"%ld",&n);
  fprintf(g,"%i\n",cifra(n));
   }
   return 0;
}