import java.util.Arrays;
import java.util.Scanner;

class Main {
	public static void main(String[] args) {
		new Main().run();
	}

	long MODULO = 1_000_000_000 + 7;

	void run() {
		Scanner sc = new Scanner(System.in);
		int n = sc.nextInt();
		if (n % 4 != 3) {
			System.out.println("O");
		}else{
			System.out.println("X");
		}
	}

	static void tr(Object... objects) {
		System.out.println(Arrays.deepToString(objects));
	}

}