class Complex:
    def __init__(self, real, imag=0.0):
        self.real = real
        self.imag = imag

    def __add__(self, other):
        return Complex(self.real + other.real, self.imag + other.imag)

    def __sub__(self, other):
        return Complex(self.real - other.real, self.imag - other.imag)

    def __mul__(self, other):
        return Complex(
            self.real * other.real - self.imag * other.imag,
            self.imag * other.real + self.real * other.imag,
        )

    def __div__(self, other):
        ar, ai, br, bi = self.real, self.imag, other.real, other.imag  # short forms
        r = float(br**2 + bi**2)
        return Complex((ar * br + ai * bi) / r, (ai * br - ar * bi) / r)

    def __abs__(self):
        return sqrt(self.real**2 + self.imag**2)

    def __neg__(self):  # defines -c (c is Complex)
        return Complex(-self.real, -self.imag)

    def __eq__(self, other):
        return self.real == other.real and self.imag == other.imag

    def __ne__(self, other):
        return not self.__eq__(other)

    def __str__(self):
        return "(%g, %g)" % (self.real, self.imag)

    def __repr__(self):
        return "Complex" + str(self)

    def __pow__(self, power):
        raise NotImplementedError("power operation is not yet impl. for Complex")

    def _illegal(self, op):
        print('illegal operation "%s" for complex numbers' % op)

    def __gt__(self, other):
        self._illegal(">")

    def __ge__(self, other):
        self._illegal(">=")

    def __lt__(self, other):
        self._illegal("<")

    def __le__(self, other):
        self._illegal("<=")

    #    def __add__(self, other):
    #        if isinstance(other, (float,int)):
    #            other = Complex(other)
    #        return Complex(self.real + other.real,
    #                       self.imag + other.imag)
    #
    #    def __radd__(self, other):
    #        return self.__add__(other)

    def __sub__(self, other):
        print("in sub, self=%s, other=%s" % (self, other))
        if isinstance(other, (float, int)):
            other = Complex(other)
        return Complex(self.real - other.real, self.imag - other.imag)

    def __rsub__(self, other):
        print("in rsub, self=%s, other=%s" % (self, other))
        if isinstance(other, (float, int)):
            other = Complex(other)
        return other.__sub__(self)