#include<iostream>
using namespace std;
class complex {
int real;
int imag;
public:
complex(int r = 0, int i = 0) {
real = r;
imag = i;
}
_________________________________
};
void add(complex& a, complex& b) {
int r = a.real + b.real;
int i = a.imag + b.imag;
cout << r << "+" << i << "i" << endl;
}
int main() {
complex x(1, 2), y(3, 4), z;
add(x, y);
} friend complex add(complex &a,complex & b) ;
friend complex add(complex &,complex &) ;
complex add(complex &a,complex & b) ;
complex add(complex ,complex ) ;