#!/usr/bin/perl
package    J   ;sub new{$__=shift and(%__)=@_ and bless{1,
$__{1},        },$__} package main; #Polymorphism  J A P H
package    A   ;sub new{$__=shift and (%__)= @_ and($___)=
J->new(        @_)and$___->{2}=$__{2}and bless($___,$__);}
package    P   ;sub new{$__=shift and (%__)= @_ and($___)=
A->new(        @_)and$___->{3}=$__{3}and bless($___,$__);}
package    H   ;sub new{$__=shift and (%__)= @_ and($___)=
P->new(        @_)and$___->{4}=$__{4}and bless($___,$__);}
$o=H->new (1,Just,2,Another,3,Perl,4,Hacker); print "$o->{
$_} "  foreach  sort  keys %{ $o } ;# Educational  Concept