# yahoo-procon2019-qualA - Anti-Adjacency
def main():
    n, k = list(map(int, input().rstrip().split()))
    print("YES" if (n + 1) // 2 >= k else "NO")


if __name__ == "__main__":
    main() def main():
    n, k = list(map(int, input().rstrip().split()))
    print("YES" if (n + 1) // 2 >= k else "NO") main n, k = list(map(int, input().rstrip().split())) n list(map(int, input().rstrip().split())) list map(int, input().rstrip().split()) map int input().rstrip().split() ().rstrip().split ().rstrip() ().rstrip () input rstrip split k print("YES" if (n + 1) // 2 >= k else "NO") print "YES" if (n + 1) // 2 >= k else "NO" (n + 1) // 2 >= k (n + 1) // 2 n + 1 n 1 2 k "YES" "NO" if __name__ == "__main__":
    main() __name__ == "__main__" __name__ "__main__" main() main def main():
    n, k = list(map(int, input().rstrip().split()))
    print("YES" if (n + 1) // 2 >= k else "NO") def main():
    n, k = list(map(int, input().rstrip().split()))
    print("YES" if (n + 1) // 2 >= k else "NO") main
# yahoo-procon2019-qualA - Anti-Adjacency
def main():
    n, k = list(map(int, input().rstrip().split()))
    print("YES" if (n + 1) // 2 >= k else "NO")


if __name__ == "__main__":
    main()