#include <bits/stdc++.h>

#define endl '\n'
#define F first
#define S second
#define pb push_back

typedef long long ll;
typedef unsigned long long ull;

using namespace std;

template<typename T>
void scan(vector<T> &v) {for (T &x : v) cin >> x;}

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

#ifdef LUCHADOR
    freopen("/home/joker/Documents/code/in", "r", stdin);
    freopen("/home/joker/Documents/code/out", "w", stdout);
#endif

    int n;
    cin >> n;

    cout << (2 * n <= 100 ? "YES" : "NO") << endl;

    return 0;
}