#include<bits/stdc++.h>
using namespace std;
int n,i=2;
int main(){
	cin>>n;
	while(i*i<=n){ 
		if(n%i==0) {
			cout<<i;
			return 0;
			} 
		i++;
		
	}
	cout<<"yes";
	return 0;
}
/**************************************************************
	Problem: 1061
	User: zhangziang
	Language: C++
	Result: Wrong Answer
****************************************************************/