#include <iostream>
using namespace std;

class A {
protected:
    int a, b;
public:
    A(int x, int y) {
        a = x;
        b = y;
    }
    virtual void print();
    friend int doubleIt(A a);
};

class B : public A {
private:
    float p, q;
public:
    B(int m, int n, float u, float v) : A(m, n){
        p = u;
        q = v;
    }
    B() : A(0, 0) { p = q = 0; }
    void input(float u, float v);
    virtual void print(float);
};
void A::print(void) {
    cout << "A values  : " << a << " " << b << "\n";
}
void B::print(float) {
    cout << "B values : " << p << " " << q << "\n";
}
void B::input(float x, float y) {
    p = x; q = y;
}

int doubleIt(A a) { return a.a * a.a; }

int main() {
    A a1(10, 20), *ptr;
    B b1;
    b1.input(7.5, 3.142);

    ptr = &a1;
    ptr->print();
    ptr = &b1;
    ptr->print();
}