#include<iostream>

class A1{
    void f1() { std::cout << "print f1" << std::endl; }
    public:
    void f2() { std::cout << "print f2" << std::endl; }
    void f5() { f1(); }
    protected:
    void f3() { std::cout << "print f3" << std::endl; }
};

class A2 : public A1{
    public:
    void f4() { f3(); }
};

int main(){
    A1 obj;
    A2 obj1;
    obj1.f4();
    obj1.f2();
    obj1.f5();
    obj.f2();
    obj.f5();
    return 0;
}