#include <fstream>

using namespace std;

ifstream in("cifra.in");
ofstream out("cifra.out");

unsigned int T,sum,c,a[30000];

int main()
{
	in>>T;
	for(unsigned int i=1;i<=T;i++)in>>a[i];
	for(unsigned int i=1;i<=T;i++)
	{
		sum=0;
		for(unsigned int j=1;j<=a[i];j++)
		{
			unsigned int aux=j;
			unsigned int b=0;
			while(aux>=9)
			{
				c=aux%10;
				aux=aux/10;
				b=1;
			}
			if(b==1)aux=c;
			else c=aux;
			unsigned int nr=1;
			while(aux!=0)
			{
				nr=nr*c;
				aux--;
			}
			sum=sum+nr%10;
		}
			if(sum>10)sum=sum%10;
			if(i!=T)out<<sum<<"\n";
			else out<<sum;
	}
	in.close();
	out.close();
	return 0;
}