my @bottles_of_beer
       = map {join "", "$_ bottle", $_ ne 1 && 's' || '', " of beer"},
             'No', 1..99;

    my $n = 99;
    while ($n > 0) {
        say "@bottles_of_beer[$n] on the wall,\n",
            "@bottles_of_beer[$n].\n",
            "Take one down, pass it around,\n",
            "@bottles_of_beer[--$n] on the wall.\n";
    }

##</code><code>##

    sub bottles {
        my ($n) = @_;

        return "No bottles" if $n == 0;
        return  "1 bottle"  if $n == 1;
        return "$n bottles";
    }

    for (reverse 1..99) {
        say  bottles($_), " of beer on the wall,";
        say  bottles($_), " of beer.";
        say  "Take one down, pass it around:";
        say  bottles($_ - 1), " of beer on the wall.";
        say  "";
    }