#include<bits/stdc++.h>
 
typedef long long ll;
using namespace std;
 
int main(){
    ios_base::sync_with_stdio(false);
    cin.tie(NULL);

    
    int x; cin>>x;
    if(2*x <=100)  cout<<"YES"<<"\n";
    else cout<<"NO"<<"\n";
    return 0;
}