import math


def resolve():
    n, k = map(int, input().split())
    print("YES" if k <= math.ceil(n / 2) else "NO")


if __name__ == "__main__":
    resolve() import math math def resolve():
    n, k = map(int, input().split())
    print("YES" if k <= math.ceil(n / 2) else "NO") resolve n, k = map(int, input().split()) n map(int, input().split()) map int input().split() ().split () input split k print("YES" if k <= math.ceil(n / 2) else "NO") print "YES" if k <= math.ceil(n / 2) else "NO" k <= math.ceil(n / 2) k math.ceil(n / 2) math.ceil math ceil n / 2 n 2 "YES" "NO" if __name__ == "__main__":
    resolve() __name__ == "__main__" __name__ "__main__" resolve() resolve def resolve():
    n, k = map(int, input().split())
    print("YES" if k <= math.ceil(n / 2) else "NO") def resolve():
    n, k = map(int, input().split())
    print("YES" if k <= math.ceil(n / 2) else "NO") resolve
import math


def resolve():
    n, k = map(int, input().split())
    print("YES" if k <= math.ceil(n / 2) else "NO")


if __name__ == "__main__":
    resolve()
