module Proverb

let finalLine (input: string list) = "And all for the want of a " + (List.head input) + "."

let getLists (input: string list) = (List.take ((List.length input) - 1) input, List.tail input)

let getItemPairs (input: string list) = 
    let lists = getLists input
    let a = lists |> fst
    let b = lists |> snd
    List.zip a b

let getLines (input: string list) = List.map (fun i -> 
    let a = i |> fst
    let b = i |> snd
    "For want of a " + a + " the " + b + " was lost.") (getItemPairs input)

let recite (input: string list): string list = if not (List.isEmpty input) then getLines input @ [finalLine input] else []