using namespace std;

class dupa{
public:
	int a1;
public:
	dupa() :a1(2)
	{
		cout << "constructor A()\n";
	}
	//dupa(dupa &a) : a1(a.a1)
	//{
	//	cout << "construtor const dupa &a\n";
	//}

	void out()
	{
		cout << "arguments:" << a1;
	}
};

class dupab : public dupa
{
public:
	dupab()
	{
		a1 += 3;
		cout << "construtor B()\n";
	}

	dupab(dupab &b)
	{
		this->a1 += b.a1;
		cout << "construtor const dupa &b\n";
	}
};

void g(dupab b)
{
	cout << b.a1;
}

int main()
{
	//dupab b;
	//b.out();
	//g(b);

	dupa a;
	dupa b = a;
	return 0;
}