let count_matches str s =
  let r = Str.regexp_string s
  and len_str = String.length str
  and len_s = String.length s
  in
  let rec count_matches' i result =
    if i >= len_str then
      result
    else
      try
        let idx = Str.search_forward r str i in
        count_matches' (idx + len_s) (result + 1)
      with Not_found -> result
  in
  count_matches' 0 0


let () =
  let s = read_line () in
  count_matches s "n"
  |> string_of_int
  |> print_endline