#include<iostream>
#include<fstream>
using namespace std;
int main ()
{
	long long T,N,s,i,j,c,k,uc;
	ifstream fin ("cifra.in");
	fin>>T;
	ofstream fout ("cifra.out");
	for(i=1;i<=T;i++)
	{
		s=0;
		fin>>N;
		for(j=1;j<=N;j++)
        {
			uc=j%10;
			c=1;
			for(k=1;k<=j;k++)
                c*=uc;
            s+=c;
        }
		fout<<s%10<<endl;
	}
	return 0;
}