class User:
    def __init__(self, login=None, password=None, first_name=None, last_name=None, phone=None):
        self.login = login
        self.password = password
        self.first_name = first_name
        self.last_name = last_name
        self.phone = phone


class Hotel:
    def __init__(self, title=None, category=None, address=None, rating=None, phone=None):
        self.title = title
        self.category = category
        self.address = address
        self.rating = rating
        self.phone = phone


class HotelCategory:
    def __init__(self, title=None, parent=None):
        self.title = title
        self.parent = None