exception UJEMNY_ARG;
let rec makeList (x : int, n : int) =
    match n with
    | 0 -> []
    | _ -> if(n < 0) then raise UJEMNY_ARG
            elif(x % 2 = 0) then List.append [x] (makeList(x + 2, n - 1))
            else (makeList(x + 1, n))