def sensible_jump(n, desired_rows=20):
    """
    return a sensible jump size to output desired_rows given input of n

    :param n:
    :param desired_rows:
    :return:
    """
    if n < desired_rows:
        return 1
    j = int(n / desired_rows)
    return round(j, -len(str(j)) + 1)