change C++ code into C#

Question

change the code below into C sharp code 

result must be the same 

 

 

---

 

 

class CA {

public: CA(int a) { a_data = a; }

protected: int a_data;

};

 

class CB : public CA {

public: CB(int b);

            void display();

private: int b_data;

};

 

CB::CB(int b) : CA(b) { b_data = b; }

void CB::display() {

      cout << "a_data = " << a_data << "\n";

      cout << "b_data = " << b_data << "\n";

}

 

void main() {

CB a(1);

a.display();

CB b(3);

b.display(1);

}