user
Task

Solve the   Towers of Hanoi   problem with recursion.
assistant
(formerly Perl 6)

```
subset Peg of Int where 1|2|3;

multi hanoi (0,      Peg $a,     Peg $b,     Peg $c)     { }
multi hanoi (Int $n, Peg $a = 1, Peg $b = 2, Peg $c = 3) {
    hanoi $n - 1, $a, $c, $b;
    say "Move $a to $b.";
    hanoi $n - 1, $c, $b, $a;
}
```