using System;
using static System.Console;
using System.Linq;
using System.Collections.Generic;

class Program
{
    static int NN => int.Parse(ReadLine());
    static long[] NList => ReadLine().Split().Select(long.Parse).ToArray();
    static void Main()
    {
        var c = NList;
        WriteLine(c[0] < Math.Abs(c[1]) ? "Yes" : "No");
    }
}