def is_uniq(values):
    """ Check if input items are unique

    Parameters
    ----------
    values : set
        set of all values

    Returns
    -------
    True/False, MULTI/unique value
    """

    if len(values) == 0:
        return True, ''
    elif len(values) == 1:
        return True, list(values)[0]
    else:
        return False, 'MULTI'