#include <iostream>
#include <fstream>

using namespace std;

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

int main()
{
    int T, N, a = 0, i, j;
    fin >> T;
    for(i = 1; i <= T; i++)
    {
        fin >> N;
        for(j = 1; j <= N; j++)
        {
         a += j*j;
        }
        fout << a%10;
    }
    return 0;
}