using System;
public class Program
{
public static void Main()
bool b = false;
int a = Int32.Parse(Console.ReadLine());
//int b = Int32.Parse(Console.ReadLine());
if(a >= 2){
//Console.WriteLine(a%2);
for(int x = 1 ; x < a; x++){
if(0 == a % x){
Console.WriteLine("No");
b = true ;
break;
}
if(!b){
Console.WriteLine("Yes");