#include <bits/stdc++.h>
using namespace std;

class Complex{
    private:
        double real;
        double imag;
    public:
        Complex();
        Complex(double real);
        Complex(double real,double imag);
        
        double getReal();
        double getImag();
        void setReal(double real);
        void setImag(double imag);
        Complex add(Complex other);
        Complex sub(Complex other);
        Complex multi(Complex other);
        Complex divide(Complex other);
        double abs();
        string toString();
};

Complex::Complex(){
    this->real=0;
    this->imag=0;
}
Complex::Complex(double real){
    this->real=real;
    this->imag=0;
}
Complex::Complex(double real,double imag){
    this->real=real;
    this->imag=imag;
}
double Complex::getReal(){
    return real;
}
double Complex::getImag(){
    return imag;
}
void Complex::setReal(double real){
    this->real=real;
}
void Complex::setImag(double imag){
    this->imag=imag;
}
Complex Complex::add(Complex other){
    return Complex(this->getReal() + other.getReal(),this->getImag() + other.getImag());
}
Complex Complex::sub(Complex other){
    return Complex(this->getReal() - other.getReal(),this->getImag() - other.getImag());
}
Complex Complex::multi(Complex other){
    double real;
    double imag;
    real=this->getReal()*other.getReal()-this->getImag()*other.getImag();
    imag=this->getReal()*other.getImag()+this->getImag()*other.getReal();
    return Complex(real,imag);
}
Complex Complex::divide(Complex other){
    double real;
    double imag; 
    real=(this->getReal()*other.getReal()+this->getImag()*other.getImag())/(pow(other.getImag(),2)+pow(other.getReal(),2));
    imag=(this->getImag()*other.getReal()-this->getReal()*other.getImag())/(pow(other.getImag(),2)+pow(other.getReal(),2));
    return Complex(real,imag);
}
double Complex::abs(){
    return sqrt(pow(this->getImag(),2)+pow(this->getReal(),2));
}
string Complex::toString(){
    string res,tmp;
    stringstream stream;
    stream<<this->getReal();
    stream>>tmp;
    res.append(tmp);
    res.append("+i");
    stream.clear();
    stream<<this->getImag();
    stream>>tmp;
    res.append(tmp);
    return res;
}

int main()
{
    Complex a(2,3);
    Complex b(4,-5);
    Complex c;
    c=a.add(b);
    cout<<c.toString()<<endl;

    c = a.sub(b);
    cout<<c.toString()<<endl;
    
    c = a.multi(b);
    cout<<c.toString()<<endl;
    
    c = a.divide(b);
    cout<<c.toString()<<endl;
    
    double res = a.abs();
    
    cout<<res<<endl;
    return 0;
}