c3e719e8 ​

let g: OList OList Color

let input = g

let output = group id (flat g)
  |> map (λ(c, ls). (c, len ls))
  |> sort (λ(c, n). -n)
  |> (λcs. gmapg (λc. if (c == cs.1.1) g (map (map (λc. black)) g)) g)