class User:
    def __init__(self, login, password):
        self._login = login
        self._password = password

    @property
    def login(self):
        return self._login

    @property
    def password(self):
        return self._password


class Operation:
    def __init__(self, a, func, b):
        self._a = a
        self._func = func
        self._b = b

    def result():
        return self._func(a, b)
