#include <fstream>
using namespace std;
int main()
{
    ifstream fin("cifra.in");
    ofstream fout("cifra.out");
    int n, nr,i,cop,sum,x;
    fin>>n;
    while(n>0) {
        fin>>nr;
        sum=0;
        for(i=1;i<=nr;i=i+1){
            cop=i;
            x=1;
            while(cop>0){
                x=x%10;
                x=x*(i%10);
                cop=cop-1;
            }
            x=x%10;
            sum = sum + x;
            sum = sum % 10;
        }
        fout<<sum<<'\n'; // endl
        n=n-1;
    }
    fin.close();
    fout.close();
    return 0;
}