#include <iostream>
    using namespace std;
    class BaseClass 
    {
        public:
        virtual void Function()
        {
            cout << "4";
        }
    };
    class DerivedClassA : public BaseClass 
    {
        public:
        void Function()
        {
            cout << " 5";
        }
    };
   class DerivedClassB : public DerivedClassA 
    {
        public:
        void Function()
        {
            cout << " 6";
        }
    };
    int main()
    {
        BaseClass *ptr;
        BaseClass BaseObject;
        DerivedClassA derivedObjectA;
        DerivedClassB derivedObjectB;
        ptr = &BaseObject;
        ptr -> Function();
        ptr = &derivedObjectA;
        ptr -> Function();
        ptr = &derivedObjectB;
        ptr -> Function();
        return 0;
    }