def find_best_step(v):
    """
    Returns best solution for given value
    :param v: value
    :return: best solution or None when no any solutions available
    """
    s = bin(v)[2:]
    r = s.find("0")

    l = len(s) - r
    if (r == -1) or ((l - 1) < 0):
        return None

    return 1 << (l - 1)