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

#define ll long long
#define endl '\n'

void solve(int cs){
    int n;
    cin>>n;
    
    cout<<(n*2 <= 100 ? "YES":"NO")<<endl;

}
   
int main()
{

    ios_base::sync_with_stdio(false);cin.tie(0);
    int t=1,cs=0;
    //cin >> t;
    while(t--)
    {
        solve(++cs);
    }

    return 0;
}