(* 基本 *)
(* ocamlc str.cma main.ml でコンパイルできる *)
let () =
  let n = Scanf.sscanf (input_line stdin) "%d" (fun a -> a) in
  let ans = if n mod 2 == 0 then n / 2 else n / 2 + 1
  in
  print_int ans;
  print_newline ()
