#include <iostream>
using namespace std;

class Base
{
  private:
      int baseval1;

  public:
    Base(int val) : baseval1(val){}

    int getvalue()
    {
       return baseval1;
    }

    void setvalue(int x)
    {
       baseval1  = x; 
        cout<<"baseval1 : "<<baseval1<<endl;
    }
   
};

class Derived : public Base
{
    public:
       Derived(int x) : Base(x){}

       void display()
       {
           //Base b;
           int num = getvalue();
           cout<<"num : "<<num<<endl;
       }
          

       void modify(int x)
        {
            //Base b;
              setvalue(x);
        } 

};


int main() {

    Derived d(10);
    d.display();
    d.modify(20);
    d.display();
    
    return 0;
}




//private datamembers of the base class can be used in derived class by usimng the member function of the base class.
// if we want to directly access the data members in the derived class then we need to make the derived class as friend class in base to access it.