using System;
using System.Linq;

class No218
{
    static void Main()
    {
        var array = new double[3];
        for (int i = 0; i < 3; ++i)
        {
            array[i] = Double.Parse(Console.ReadLine());
        }
        var h = Math.Ceiling(array[0] / array[1] / 3* 2) ;
        Console.WriteLine(h * array[2] >= array[0] ? "YES" : "NO");
    }
}