def get_short_id_from_lb2_arn(alb_arn: str) -> str:
    """
    Return the (A|N)LB name from the ARN
    For example, for arn:aws:elasticloadbalancing:::loadbalancer/app/foo/ab123", return 'foo'.
    For example, for arn:aws:elasticloadbalancing:::loadbalancer/net/foo/ab123", return 'foo'.
    :param arn: The (N|A)LB's full ARN
    :return: The (N|A)LB's name
    """
    return alb_arn.split('/')[-2]