Codechef Round

#include <bits/stdc++.h>
using namespace std;



void solve(){
    
     int i,j,n,m,k;
     cin>>n;
     if(n==4)
     cout<<"YES"<<endl;
     else
     cout<<"NO"<<endl;

}

int main() {
    ios_base::sync_with_stdio(false);
    cin.tie(NULL);

    int t=1;
    while(t--){
    solve();
    }
    return 0;
}