Hackerrank helper for OCaml

hackerrank.ml

let rec read_lines () =
    try let line = read_int () in
        line :: read_lines ()
    with
        _ -> []
;;

let f ls =
    (* write your code here *)
;;

let () =
    let ls = read_lines() in
    let ans = f ls in
    List.iter (fun x -> print_int x; print_newline ()) ans
;;