import java.util.*;
public class Test10 {
  public static void main(String[] args){
    Scanner sc=new Scanner(System.in);
    String line;
    line=sc.nextLine();
    int a=Integer.parseInt(line),n=1+2;
    String result="NO";
    if(a>=2) result="YES";
    System.out.println(result);
    sc.close();
  }
}