#include<bits/stdc++.h>
using namespace std;
#define optimize() ios_base::sync_with_stdio(0);cin.tie(0);cout.tie(0);
#define endl '\n'
#define ll long long int
int main()
{
    optimize();
    int n;
    cin>>n;
    if((n*2)<=100)cout<<"YES"<<endl;
    else cout<<"NO"<<endl;
    return 0;
}