let read_numbers filename =
  let ic = open_in filename in
  let rec loop acc =
    try
      let line = input_line ic in
      let n = int_of_string line in
      loop (n::acc)
    with
      End_of_file -> List.rev acc
  in
  let numbers = loop [] in
  close_in ic;
  print_numbers numbers;
  numbers
;;