import java.io.BufferedReader;
import java.io.InputStreamReader;

public class Main {
	public static void main(String[] args) {
		BufferedReader read = new BufferedReader(new InputStreamReader(System.in));

		try {
			int a = Integer.parseInt(read.readLine());
			int b = Integer.parseInt(read.readLine());
			int c = Integer.parseInt(read.readLine());

			double normal = (a * 1.0) / b;
			if (normal % 1 > 0) {
				normal = (int) (normal + 1);
			}
			normal *= 2d / 3d;

			double campaign = normal * c;

			if (a > campaign) {
				System.out.println("NO");
			} else {
				System.out.println("YES");
			}

		} catch (Exception e) {
			e.printStackTrace();
		}
	}
}