#include <iostream>
using namespace std;


/*
Try this sample with vritual just on Person::Hello(), then virtual just on Student::Hello(),
then virtual just on UGrad::Hello()
*/
class Person{
public:
  void Hello()
  {
    cout<<"Person::Hello()\n";
  }
protected:
  int SS_Num;
};

class Student : public Person{
public:
  void Hello()
  {
    cout<<"Student::Hello()\n";
  }
protected:
  int Student_Num;
};

class UGrad : public Student{
public:
  virtual void Hello()
  {
    cout<<"UGrad::Hello()\n";
  }
};

class Senior : public UGrad{
public:
  void Hello()
  {
    cout<<"Senior::Hello()\n";
  }
};

int main()
{
  Person P1;
  Student S1;
  UGrad U1;
  Senior SE1;

  Person *pptr;
  Student *sptr;
  UGrad *uptr;
  Senior *septr;


  pptr = &P1;
  pptr->Hello();

  pptr = &S1;
  pptr->Hello();
  
  pptr = &U1;
  pptr->Hello();

  pptr = &SE1;
  pptr->Hello();

  cout<<"***********************\n";

  //sptr = &P1;
  //sptr->Hello();

  sptr = &S1;
  sptr->Hello();
  
  sptr = &U1;
  sptr->Hello();

  sptr = &SE1;
  sptr->Hello();

  cout<<"***********************\n";

  //uptr = &P1;
  //uptr->Hello();

  //uptr = &S1;
  //uptr->Hello();

  uptr = &U1;
  uptr->Hello();

  uptr = &SE1;
  uptr->Hello();

  return 0;
}