sub hanoi {
    my ($n, $a, $b, $c) = @_;
    
    return if $n < 1;

    hanoi($n-1, $a, $c, $b);
    print "Moving plate from $a to $b\n";
    return hanoi($n-1, $c, $b, $a);
}

-- Example of call
$ hanoi(8, "A", "B", "C")
=> 2^8 - 1 moves
    
-- Comment
   $n is the number of plates (> 0) to move
   from pole A to pole B using auxiliary pole C 
   
   The final 'return' allows for a slight
   tail-call optimization