#include<iostream>
#include<fstream>

using namespace std;

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


long long int n,T,suma,u;

int main ()
{
    int i,j,k,aux;
    fin>>T;
    for (i=1; i<=T; i++)
    {
        fin>>n;
        suma=0;

        for (j=1; j<=n; j++)
        {
            aux=j%10;
            u=aux;
            for (k=2; k<=j; k++)
            {
                u=(u*aux)%10;
            }
            suma=(suma+u)%10;
        }
        fout<<suma<<"\n";
    }

    fout<<"\n";
    fin.close();
    fout.close();
    return 0;
}