object Main extends App {
  import scala.io.StdIn._


  val Array(n, k) = readLine.trim.split(' ').map(_.toInt)
  println(if ((n + 1) / 2 >= k) "YES" else "NO")
  implicit class Scope[T](val value: T) extends AnyVal {
    @inline def also(@inline func: T ⇒ Unit): T = {
      func(value)
      value
    }
    @inline def let[A](@inline func: T ⇒ A): A = func(value)
  }
}