import java.io.PrintWriter; import java.util.ArrayList; import java.util.Arrays; import java.util.Collections; import java.util.HashMap; import java.util.List; import java.util.PriorityQueue; import java.util.Scanner; public class Main { public static long MOD = 1000000007; public static void main(String[] args) { Scanner sc = new Scanner(System.in); final long N = sc.nextLong(); System.out.println((N == 1 || Long.toBinaryString(N).contains("0")) ? "O" : "X"); } }