Imports System.Collections.Generic
Imports System.Console
Imports System.Math  
Module Program
 	Sub Main()
        Dim input() As String = Console.ReadLine().Split(" ")
        Dim N As Integer = input(0)
        Dim K As Integer  = input(1)
        Console.WriteLine(IIF((N-1)/2>=K-1, "YES", "NO"))
    End Sub
End Module
