exm.java

abstract class abstractest {
 abstract void a1();

 public void a2(){
 
  System.out.println("hello world");
 
 }

}

class absed extends abstractest
{
 void a1()
 {System.out.println("hello");
  }

}

public class exm
{
 
public static void main(String args[])
{
abstractest a = new absed();
a.a1();
a.a2();
}

}