class animal{
    animal(){
        System.out.println("this is parent class animal");
    }
}
class cat extends animal{
    cat(){
        System.out.println("this is cat class");
    }
}
class kitten extends cat{
    kitten(){
        System.out.println("this is kitten class");
    }
    
}
public class Main{
    public static void main(String[] args){
        kitten obj=new kitten();
    }
}