#!/usr/bin/perl -w

use strict;
use Lingua::EN::Nums2Words; 

my $beer = shift || 99;
$beer = abs($beer);

for (-9..$beer) {
    print how_many($beer), ",\n",
       how_many($beer), ".\n",
       "Take one down, pass it around,\n",
       how_many(--$beer), ".\n\n"
}

sub how_many {
   my $numb = &num2word(shift);
   $numb =~ s/(\w)(.*)/\u$1\L$2/;  
   return $numb
      . ' bottle' 
      . ($numb eq 'One' ? '' : 's')
      . ' of beer on the wall'
   ;
}