#include <iostream>

/*

#include <conio.h>

#include<stdio.h>

#include<iomanip>

#include<string>

#include<sstream>

*/

using namespace std;

class complex

{

    double real,imag;

public:

    complex(double,double);

    void disp(char *);

    friend complex operator + (complex,complex);

    friend complex operator - (complex,complex);

    friend complex operator * (complex,complex);

    friend complex operator / (complex,complex);

};

complex::complex (double r=,double i=)

{

    real = r;

    imag = i;

}

void complex::disp (char *str)

{

    cout.unsetf(ios::showpos);

    cout<<str<<"="<<real;

    if (imag)

    {

        cout.setf(ios::showpos);

        cout<<imag<<'i';

    }

    cout<<endl;

    cout.unsetf(ios::showpos);

}

complex operator + (complex cpl1,complex cpl2)

{

    double t=cpl1.real+cpl2.real;

    double i=cpl1.imag+cpl2.imag;

    return complex(t,i);

}

complex operator - (complex cpl1,complex cpl2)

{

    double t=cpl1.real-cpl2.real;

    double i=cpl1.imag-cpl2.imag;

    return complex(t,i);

}

complex operator * (complex cpl1,complex cpl2)

{

    double t=cpl1.real*cpl2.real - cpl1.imag*cpl2.imag;

    double i=cpl1.real*cpl2.imag + cpl1.imag*cpl2.real;

    return complex(t,i);

}

complex operator / (complex cpl1,complex cpl2)

{

    double t=(cpl1.real*cpl2.real+cpl1.imag*cpl2.imag)/(cpl2.real*cpl2.real+cpl2.imag*cpl2.imag);

    double i=(cpl1.imag*cpl2.real-cpl1.real*cpl2.imag)/(cpl2.real*cpl2.real+cpl2.imag*cpl2.imag);

    return complex(t,i);

}

int main(void)

{

    complex c1(,),c2(,),c3();

    c1.disp("c1");

    c2.disp("c2");

    c3=c1+c2;

    c3.disp("c3");

    c3=c1-c3;

    c3.disp("c3");

    c3=c1*c2;

    c3.disp("c3");

    c3=c1/c2;

    c3.disp("c3");

    getchar();

    return ;

}