package no036;

import java.math.BigInteger;
import java.util.Scanner;

public class Main {

	public static void main(String[] args) {
		Scanner sc = new Scanner(System.in);
		BigInteger bi = new BigInteger(sc.next());
		if (bi.intValue() == 1) {
			System.out.println("NO");
			return;
		}
		System.out.println(bi.isProbablePrime(30) ? "NO" : "YES");
	}

}