def main():
    N, K = (int(i) for i in input().split())
    if (N+1)//2 >= K:
        print("YES")
    else:
        print("NO")


if __name__ == '__main__':
    main() def main():
    N, K = (int(i) for i in input().split())
    if (N+1)//2 >= K:
        print("YES")
    else:
        print("NO") main int(i) for i in input().split() for i in input().split() i input().split() ().split () input split for i in input().split() int(i) int i N, K = (int(i) for i in input().split()) N (int(i) for i in input().split()) K if (N+1)//2 >= K:
        print("YES")
    else:
        print("NO") (N+1)//2 >= K (N+1)//2 N+1 N 1 2 K print("YES") print "YES" print("NO") print "NO" if __name__ == '__main__':
    main() __name__ == '__main__' __name__ '__main__' main() main def main():
    N, K = (int(i) for i in input().split())
    if (N+1)//2 >= K:
        print("YES")
    else:
        print("NO") def main():
    N, K = (int(i) for i in input().split())
    if (N+1)//2 >= K:
        print("YES")
    else:
        print("NO") main
def main():
    N, K = (int(i) for i in input().split())
    if (N+1)//2 >= K:
        print("YES")
    else:
        print("NO")


if __name__ == '__main__':
    main()
