#include <iostream>
#include <fstream>

using namespace std;

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

int ucif(int p)
{
    int ucif = p % 10;
    int aux = p - 1;
    while(aux)
    {
        ucif = (ucif * p) % 10;
        aux--;
    }
    return ucif;
}

int suma(int n)
{
    int cif = 0;
    for (int i = 1; i <= n; i++)
    {
        cif += ucif(i);
        //cif %= 10;
    }
    cif %= 10;
    return cif;
}

int main()
{
    int T;
    int n;
    fin >> T;
    while (T)
    {
        fin >> n;
        fout << suma(n) << endl;
        T--;
    }
    return 0;
}