#include <fstream>
using namespace std;

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

int uc,uctotal,i,t;
char n,k,j;

int main()
{
    fin>>t;

    for(i=1;i<=t;i++){
        fin>>n;
        uctotal = 0;

        for(j=1;j<=n;j++){
            k = j;
            uc = j;
            while(k != 1){
                uc = (j*uc) % 10;
                k = k-1;
            }

            uctotal += uc;
            if (uctotal > 9)
                uctotal = uctotal % 10;
        }
        fout<<uctotal<<"\n";


    }


    return 0;
}