import java.util.Scanner;

public class Main{
    public static void main(String[] args){
        Scanner sc = new Scanner(System.in);
        int N = sc.nextInt();

        int divisorCount = 0;
        for(int i=0; i<=Math.pow(N, 0.5); i++){
            if(N%i == 0){
                divisorCount++;
            }
            if(divisorCount==2){
                System.out.println("YES");
                break;
            }
        }
        System.out.println("No");
    }
}