public class Test1 {
  public static void main(String[] args) {
    Person[] p = { new Student(123456),  
      new Faculty(123456) };
    for (int i=0; i<p.length; i++)
      System.out.println(p[i].getID());
  }
}

class Person {
  protected int id;
  public Person(int id) {this.id = id;}
  public int getID() { return id; }
} 
class Student extends Person { 
  public Student(int id) { super(id); } 
}
class Faculty extends Person {
  public Faculty(int id) { super(id); this.id *= 10; }
}