#include <stdio.h>
FILE *f=fopen("cifra.in","r"), *g=fopen("cifra.out","w");
int prod(long x)
{
	long i,p;
	int k;
	p=x;
	while (x>10)
		x/=10;
	k=x;
	if ((k==0)||(k==1)) return k;
	for (i=2;i<=p;i++)
		k=(k*x)%10;
	return k;
}
int main()
{
int s=0,t,i,k,p,j;
long n[10000];
fscanf(f,"%d",&t);
for (i=1;i<=t;i++)
{
        s=0;
	fscanf(f,"%ld",&n[i]);
	for (j=1;j<=n[i];j++)
		{
		s+=prod(j);
		s%=10;
		}
	fprintf(g,"%d\n",s);
}
fcloseall();
return 0;
}