Scanf.scanf "%d" (fun n ->
    let x = Array.init n (fun _ -> Scanf.scanf " %d" (fun x -> x)) in
    let rec loop i ev od =
        if i = n then n - min ev od * 2 else
            if abs x.(i) mod 2 = 0 then loop (i + 1) (ev + 1) od
                                   else loop (i + 1) ev (od + 1)
    in
    loop 0 0 0 |> Printf.printf "%d\n"
)