def purify_preferences(preferences: str, separator: str = ' ') -> list:
    """Removes the integer string from the specified preferences string and sorts it.

    Args:
        preferences (str): Preferences string of type L(ike) or D(islike).
        separator (str, optional): Seperator for splitting the preferences string. Defaults to ' '.

    Returns:
        list: A purified preference in form of a sorted list of strings.
    """
    preference_list = preferences.split(separator)
    num_preferences = int(preference_list[0])
    pure_preferences = ['none'] if (num_preferences == 0) else preference_list[1:]
    return pure_preferences