package ClassA;

use strict;

use base qw(fields);
use fields qw(id name);

sub new {
  my $class = shift;
  $class->SUPER::new();
}

sub getclass
{
  my $self = shift;
  return ref($self);
}

1;

##</code><code>##

package ClassB;

use strict;

use base qw(ClassA);
use fields qw(addr phone city);

use ClassC;

sub addC
{
  my $self = shift;
  $self->{c} = ClassC->new();
}
1;

##</code><code>##

package ClassC;

use strict;

use base qw(ClassA);
use fields qw(model type);

sub addB
{
  my $self = shift;
  $self->{b} = ClassB->new();
}
1;

##</code><code>##

#!/usr/bin/perl -l
# Test program
use ClassA;
use ClassB;
use ClassC;

my $a = ClassA->new();
my $b = ClassB->new();
my $c = ClassC->new();

print $a->getclass();
print $b->getclass();
print $c->getclass();

$b->{name} = 'bee';
print $b->{name};

$c->{name} = 'see';
print $c->{name};

$b->{city} = 'wok';
print $b->{city};

$c->{model} = 't';
print $c->{model};