#!/usr/bin/perl -w
use strict;

use Default;
use Upper;
use Lower;

my $arg = shift || '';

my %handlers = (
	default => Default->new,
	upper   => Upper->new,
	lower   => Lower->new,
);

my $ref = $handlers{$arg} || $handlers{'default'};

print $ref->handle("AaAaAaAa"), "\n";