let solve n c_lst =
  let c_sum = List.fold_left (fun s c -> s + c) 0 c_lst in
  let th = c_sum / 10 in

  let rec solve' lst result =
    match lst with
    | [] -> result
    | x::xs ->
      let result = if x <= th then result + 1 else result in
      solve' xs result
  in
  solve' c_lst 0
  |> fun r -> r * 30

let () =
  let n = read_line () |> int_of_string
  and c_lst = read_line ()
              |> Str.split (Str.regexp_string " ")
              |> List.map int_of_string
  in
  solve n c_lst
  |> string_of_int
  |> print_endline