using System;
using System.Collections.Generic;
using System.Linq;
using System.Text;
using System.Threading.Tasks;

class Program
{
    static void Main(string[] args)
    {
        new Magatro().Solve();
    }
}

class Magatro
{

    public void Solve()
    {
        uint N = uint.Parse(Console.ReadLine());
        Console.WriteLine(N % 4 == 3 ? "X" : "O");
    }
}