import java.math.BigInteger;

 import java.util.Scanner;

 public class Main {

     public static void main(String[] args) {

         Scanner cin = new Scanner(System.in);

         BigInteger a = cin.nextBigInteger();

         Boolean b = a.isProbablePrime();

         if(b == true)

             System.out.println("Yes");

         else

             System.out.println("No");

         cin.close();

     }

 }