#include <iostream>

using namespace std;

class A {
public:
        virtual void pr() {cout << "A";}
};

class B : public A {
public:
        void pr() override {cout << "B";}
};


int main() {
        A *x = new A;
        x->pr();

        B y;
        y.pr();

        x = &y;
        x->pr();
        return 0;
}


// OUTPUT: ABB