// Problem Solver: Mushfiq R.
#include <iostream>
using namespace std;

int main()
{
    ios_base::sync_with_stdio(false);
    cin.tie(NULL);
    cout.tie(NULL);
    int n;
    cin >> n;
    if (2 * n <= 100)
    {
        cout << "YES\n";
    }
    else
    {
        cout << "NO\n";
    }

    return 0;
}