#include <iostream>
#include <cmath>
#include <functional>
using namespace std;
int zero='a'%'a';
int one='b'%'a';
int two='c'%'a';
int p(int n){
	if(n==one)return false;
	for(int i=two;i<=sqrt(n);i=plus<int>()(i,one)){
		if(n%i==zero){
			return false;
		}
	}
	return true;
}
int main() {
	int n;cin>>n;
	cout<<(p(n)?"YES":"NO")<<endl;
}