
def main():
    a, b = map(int, input().split())

    if (a + 1) // 2 >= b:
        print('YES')
    else:
        print('NO')



if __name__ == '__main__':
    main() def main():
    a, b = map(int, input().split())

    if (a + 1) // 2 >= b:
        print('YES')
    else:
        print('NO') main a, b = map(int, input().split()) a map(int, input().split()) map int input().split() ().split () input split b if (a + 1) // 2 >= b:
        print('YES')
    else:
        print('NO') (a + 1) // 2 >= b (a + 1) // 2 a + 1 a 1 2 b print('YES') print 'YES' print('NO') print 'NO' if __name__ == '__main__':
    main() __name__ == '__main__' __name__ '__main__' main() main def main():
    a, b = map(int, input().split())

    if (a + 1) // 2 >= b:
        print('YES')
    else:
        print('NO') def main():
    a, b = map(int, input().split())

    if (a + 1) // 2 >= b:
        print('YES')
    else:
        print('NO') main

def main():
    a, b = map(int, input().split())

    if (a + 1) // 2 >= b:
        print('YES')
    else:
        print('NO')



if __name__ == '__main__':
    main()