#include <iostream>
#include<string>
using namespace std;

class Person {
public:
    Person() :name(""), address("") {}
    Person(string n, string a) :name(n), address(a) {}
    virtual void display(){
        cout << name << endl;
        cout << address << endl;
    }
private:
    string name;
    string address;
};

class Student : public Person {
public:
    Student() :major("") {}
    Student(string n, string a, string m) :Person(n, a), major(m) {};
    void display() {
        Person::display();
        cout << major << endl;
    }
private:
    string major;
};

class Instructor :public Person {
public:
    Instructor() :salary(0) {}
    Instructor(string n, string a, double s) :Person(n, a), salary(s) {}
    void display() {
        Person::display();
        cout << salary << endl;
    }
private:
    double salary;
};

void displayObject(Person& p) {
    p.display();
}

int main()
{
    Person p("Person", "Blagoevgrad");
    Student s("Student", "Blagoevgrad", "COS");

    displayObject(p);
    cout << endl;
    displayObject(s);
    cout << endl;

    return 0;
}