#include<bits/stdc++.h>
using namespace std;
int main(){
	int a;
	cin>>a; 
	if(a/2==1){
		cout<<"yes";
	}
}
/**************************************************************
	Problem: 1641
	User: wangyiyang
	Language: C++
	Result: Accepted
	Time:37 ms
	Memory:2072 kb
****************************************************************/