# -*- coding: utf-8 -*-


def main():
    from math import ceil
    n, k = map(int, input().split())

    if ceil(n / 2) < k:
        print('NO')
    else:
        print('YES')


if __name__ == '__main__':
    main() def main():
    from math import ceil
    n, k = map(int, input().split())

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

    if ceil(n / 2) < k:
        print('NO')
    else:
        print('YES') def main():
    from math import ceil
    n, k = map(int, input().split())

    if ceil(n / 2) < k:
        print('NO')
    else:
        print('YES') main
# -*- coding: utf-8 -*-


def main():
    from math import ceil
    n, k = map(int, input().split())

    if ceil(n / 2) < k:
        print('NO')
    else:
        print('YES')


if __name__ == '__main__':
    main()
