#include <iostream>
using namespace std;
class D;
class B {
int x;
friend void f(B, D);
public:
B(int i = 0) { x = i; }
};
class D : public B {
public:
int y;
D(int i = 0, int j = 0)
: B(i)
{
y = j;
}
};
void f(B b, D d) { cout << b.x << " " << d.y; }
int main()
{
B b;
D d;
f(b, d);
}