module ArrayL = ArrayLabels
module ListL = ListLabels

let dbg = Printf.printf "[debug]%s"

let max_num = 100_000_000_000

let id = fun x -> x
let tuple2 x y = (x,y)
let tuple3 x y z = (x,y,z)
let succ x = x + 1
let pred x = x - 1

let (++) n m =
  let rec aux i =
    if i = m then [m]
    else i :: aux (i+1) in
  if n > m then [] else aux n

let (++^) n m = n ++ (m-1)

let scan fmt f = Scanf.sscanf (read_line ()) fmt f

let scan_lines n fmt f =
  List.map (fun _ -> scan fmt f) (0++^n)

let scan_matrix n m e conv =
  let arr = Array.make_matrix n m e in
  Array.iteri (fun i line ->
      let s = Scanf.Scanning.from_string @@ read_line () in
      Array.iteri (fun j _ ->
          arr.(i).(j) <- Scanf.bscanf s " %s" conv;
        ) line) arr; arr

let between n x m = n <= x && x < m

let string_to_list s =
  List.map (String.get s) (0 ++^ String.length s)

let () =
  let rec aux n i =
    if n = 1 then
      Printf.printf "\n"
    else if i * i > n then
      Printf.printf " %d\n" n
    else if n mod i = 0 then
      (Printf.printf " %d" i;
       aux (n/i) i)
    else aux n (succ i)
  in
  let n = scan "%d" id in
  Printf.printf "%d:" n;
  aux n 2

