def main():

    N, K = map(int, input().split())
    if (N+1) // 2 >= K:
        return "YES"
    return "NO"


if __name__ == '__main__':
    print(main()) def main():

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

    N, K = map(int, input().split())
    if (N+1) // 2 >= K:
        return "YES"
    return "NO" def main():

    N, K = map(int, input().split())
    if (N+1) // 2 >= K:
        return "YES"
    return "NO" main
def main():

    N, K = map(int, input().split())
    if (N+1) // 2 >= K:
        return "YES"
    return "NO"


if __name__ == '__main__':
    print(main())