#include <math.h>
#include <iostream>

class Complex
{
private:
	double Re_{};
	double Im_{};
public:
	double Re() const noexcept {
		return Re_;
	}
	double Im() const noexcept {
		return Im_;
	}
	void SetRe(double x) noexcept {
		Re_ = x;
	}
	void SetIm(double x) noexcept {
		Im_ = x;
	}
	Complex() {
		this->Re_ = 0.0;
		this->Im_ = 0.0;
	}
	Complex(double re) {
		this->Re_ = re;
		this->Im_ = 0.0;
	}
	Complex(double re, double im) {
		this->Re_ = re;
		this->Im_ = im;
	}
	Complex operator+() const noexcept {
		return *this;
	}
	Complex operator-() const noexcept {
		return { -Re(), -Im() };
	}
	friend Complex operator+(Complex a, const Complex& b) {
		return { a.Re() + b.Re(), a.Im() + b.Im() };
	}
	friend Complex operator-(Complex a, const Complex& b) {
		return { a.Re() - b.Re(), a.Im() - b.Im() };
	}
	friend Complex operator*(Complex a, const Complex& b) {
		return { a.Re() * b.Re() - a.Im() * b.Im(), a.Re() * b.Im() + b.Re() * a.Im() };
	}
	friend Complex operator/(Complex a, const Complex& b) {
		return { ((a.Re() * b.Re() + a.Im() * b.Im()) / (b.Re() * b.Re() + b.Im() * b.Im())),
			((b.Re() * a.Im() - (a.Re() * b.Im())) / (b.Re() * b.Re() + b.Im() * b.Im())) };
	}
	friend bool operator==(const Complex& a, const Complex& b) {
		return (a.Re() == b.Re() && a.Im() == b.Im());
	}
	friend bool operator!=(const Complex& a, const Complex& b) {
		return !(a == b);
	}
};

double abs(Complex a) {
	return std::sqrt(a.Re() * a.Re() + a.Im() * a.Im());
}

std::ostream& operator<<(std::ostream& os, const Complex& a) {
	os << a.Re() << ' ' << a.Im() << "i";
	return os;
}
std::istream& operator>>(std::istream& is, Complex& a) {
	double Re, Im;
	std::cout << "Complex: ";
	is >> Re >> Im;
	std::cout << '\n';
	a.SetRe(Re);
	a.SetIm(Im);
	return is;
}

int main()
{
    Complex a, b;
    std::cin >> a >> b;
    std::cout << a + b << '\n';
    std::cout << a + 4 << '\n';
    std::cout << a - 2 << '\n';
    std::cout << 2 - a << '\n';
    std::cout << a - b << '\n';
    std::cout << a * b << '\n';
    std::cout << a / b << '\n';
    std::cout << (a == b) << '\n';
    std::cout << (a != b) << '\n';
    std::cout << abs(a) << '\n';
    std::cout << abs(b) << '\n';
}