let solve arr =
  let rec solve' idx rem result =
    if idx >= 10 then result + rem / 4
    else
      let next_rem, next_result =
        rem + arr.(idx) mod 2, result + arr.(idx) / 2
      in
      solve' (idx + 1) next_rem next_result
  in
  solve' 0 0 0

let read_abc in_seq =
  let arr = Array.make 10 0 in
  Stream.iter (fun (a, b, c) ->
    arr.(a) <- arr.(a) + 1;
    arr.(b) <- arr.(b) + 1;
    arr.(c) <- arr.(c) + 1) in_seq;
  arr

let () =
  let n = read_line () |> int_of_string in
  let in_seq = Stream.from (fun i ->
    if i >= n then None
    else
      read_line () |>
      Str.split (Str.regexp_string " ") |>
      List.map int_of_string |>
      fun lst -> Some (List.nth lst 0 - 1,
                       List.nth lst 1 - 1,
                       List.nth lst 2 - 1))
  in
  let arr = read_abc in_seq in
  solve arr |> string_of_int |> print_endline