module _32

open common

let panDigitalProduct =
    crossMapList [12..98] [123..987]
    |> Seq.append (crossMapList [1..9] [1234..9876])
    |> Seq.map (fun (x,y) -> [x;y;x*y])
    |> Seq.filter ((List.map unbox) >> isPanDigitalGroup)
    |> Seq.map (fun l -> l.[2])
    |> Seq.distinct
    |> Seq.sum