class Person
{
  String name=null;
  int age=0;
  Person(String n, int a)
  {
    name=n;
    age=a;
  }
 void display()
  {
    System.out.println("name=" +name);
  }
}

class Student extends Person
{
  int rollNo=0;
  String course=null;
  Student(String n, int a, String c, int r)
  {
    super(n,a);
    rollNo=r;
    course=c;
  }
   public void display()
   {
     super.display();
     System.out.println("Course= "+course+"Roll No="+rollNo);
   }
}

class CheckMain
{
  public static void main(String args[])
  {
    Person p= new Person("Rahul",25);
    p.display();
    Student s1= new Student("John",20,"BCA",4093);
    s1.display();
    // variable may be passed instead of static value
  }
}