#include <iostream>
using namespace std;

class A
{
public:
	A() { f(); }
	virtual void f() { std::cout << "A::f()\n"; }
};

class B : public A
{
public:
	void f() { std::cout << "B::f()\n"; }
};

int main() {
	// your code goes here
	B b;
	return 0;
}