How To Add Two complex Numbers Using C++ class

#include <iostream>
#include <conio.h>
using namespace std;
class complex
{
public :
int real, img;
};
int main()
{
complex a, b, c;
cout << "Enter a and b where a + ib is the first complex number.";
 cout << "\na = ";
 cin >> a.real;
cout << "b = "; cin >> a.img;
cout << "Enter c and d where c + id is the second complex number.";
 cout << "\nc = "; 
 cin >> b.real;
cout << "d = ";
 cin >> b.img;
c.real = a.real + b.real;
c.img = a.img + b.img;
if ( c.img >= 0 )
cout << "Sum of two complex numbers = " << c.real << " + " << c.img << "i"; 
 else
 cout << "Sum of two complex numbers = " << c.real << " " << c.img << "i";
 return 0; 
}