#include <iostream>
#include <string>
#include <algorithm>

using namespace std;

int main() {
	int A, B, C;
	int X, Y;

	cin >> A >> B >> C;

	if(A % B  == 0) X = A / B;
	else X = A / B + 1;

	Y = C * (X * 2 / 3);

	if (Y >= A) cout << "YES" << endl;
	else cout << "NO" << endl;
	return 0;
}