#!/usr/bin/perl -w

use strict;

my $beer = abs shift || 99;

print how_many($beer), ",\n",
   how_many($beer), ".\n",
   "Take one down, pass it around,\n",
   how_many(--$beer), ".\n\n"
while $beer;

sub how_many {
   my $numb = shift;
   return $numb 
      . ' bottle' 
      . ($numb == 1 ? '' : 's')
      . ' of beer on the wall'
   ;
}