use proconio::input;

fn main() {
    // let mut stdin = LineSource::new(BufReader::new(io::stdin()));
    // macro_rules! input(($($tt:tt)*) => (proconio::input!(from &mut stdin, $($tt)*)));
    input! {
        n:usize,
    }
    println!("{}", if n % 4 != 3 { "O" } else { "X" });
}