class Example1{

   public void display1(){

      System.out.println("display1 method");

   }

}

abstract class Example2{

   public void display2(){

      System.out.println("display2 method");

   }

}

abstract class Example3 extends Example1{

   abstract void display3();

}

class Example4 extends Example3{

   public void display3(){

      System.out.println("display3 method");

   }

}

class Demo{

   public static void main(String args[]){

       Example4 obj=new Example4();

       obj.display3();

   }
}