#include<bits/stdc++.h>
using namespace std;
int main(){
    int a;
    cin>>a; 
    if(a/2==1){
        cout<<"yes";
    }
}
/**************************************************************
	Problem: 1640
	User: wngjinming
	Language: C++
	Result: Accepted
	Time:4 ms
	Memory:2072 kb
****************************************************************/