class BaseClass {

   public final void show(Object o) {

      System.out.println("BaseClass method");

   }

}

class DerivedClass extends BaseClass {

   public void show(Integer i) {

      System.out.println("DerivedClass method");

   }

}

public class Test {

   public static final void main(String[] args) { // declaring main () method with final keyword.

      BaseClass b = new BaseClass();

      DerivedClass d = new DerivedClass();

      b.show(new Integer(0));

      d.show(new Integer(0));

   }

}