#include <iostream>
#include <fstream>
using namespace std;

int main()
{
    int n,i,j,nr,t,s;
    ifstream fin("cifra.in");
    ofstream fout("cifra.out");
    fin>>n;
    while(n)
    {
        fin>>nr;
        s=0;
        while(nr)
        {
            i=1;
            t=nr;
            while(t)
            {
                i*=nr;
                i=i%10;
                t--;
            }
            nr--;
            s+=i;
            s=s%10;
        }
        cout<<s<<"\n";
        n--;

    }
    return 0;
}