for 99...1 -> $counter {
    sing $counter, :wall;
    sing $counter;
    say  "Take one down, pass it around";
    sing $counter - 1, :wall;
    say  "";
}

#| Prints a verse about a certain number of beers, possibly on a wall.
sub sing(
    Int $bottles, #= Number of bottles of beer.
    Bool :$wall #= Mention that the beers are on a wall?
) {
    my $quantity = $bottles == 0 ?? "No more"      !! $bottles;
    my $plural   = $bottles == 1 ?? ""             !! "s";
    my $location = $wall        ?? " on the wall" !! "";
    say "$quantity bottle$plural of beer$location"
}