class Calculator:
    def __init__(self, brand, model):
        self._brand = brand
        self._model = model

    def __str__(self):
        return '{brand} {model} is ready to work!'.format(brand=self._brand, model=self._model)

    def add(self, first, second):
        return first + second

    def substract(self, first, second):
        return first - second

    def multiply(self, first, second):
        return first * second

    def divide(self, first, second):
        return first / second

    def integer_division(self, first, second):
        return first // second

    def modulo(self, first, second):
        return first % second

if __name__ == "__main__":
    calc = Calculator('Casio', 2000)
    print(calc.__str__())
    print(calc.add(3, 4))
    print(calc.substract(3, 4))
    print(calc.multiply(3, 4))
    print(calc.divide(3, 4))
    print(calc.integer_division(3, 4))