let read_int_array n = Array.init n (fun _ -> Scanf.scanf " %d" (fun x -> x))

let () =
  let n = read_int() in
  let a = read_int_array n in

  let rec solve i count =
    if i = n then count
    else
      let flag = i mod 2 = 0 && a.(i) mod 2 = 1 in
      let x = if flag then 1 else 0 in
      solve (i + 1) (count + x) in

  let ans = solve 0 0 in
  Printf.printf "%d\n" ans
