Scanf.scanf "%s" (fun s ->
    let n = String.length s in
    let rec loop i c w =
        if i = n then min (c - 1) w else
            if s.[i] = 'c' then loop (i + 1) (c + 1) w
                           else loop (i + 1) c (w + 1)
    in
    loop 0 0 0 |> Printf.printf "%d\n"
)