def arrival_to_str(arrival):
    """

    :param arrival: list (minutes, seconds, stops)
    :return: arrival string
             example : '4m(3)' for 4 minutes and 3 stops left
    """

    arrival_str = "----"

    if arrival is not None:
        # omit seconds
        arrival_str = '{}m({})'.format(arrival[0], arrival[2])

    return arrival_str