let () =
  let rec charlist_of_string str n i =
    if i = n then [] else str.[i] :: charlist_of_string str n (i+1) in
  let rec count lst ans buf = match lst with
    | [] -> if buf > ans then buf else ans
    | h :: t ->
      if h = 'o' then if ans < buf + 1 then count t (buf+1) (buf+1) else count t ans (buf+1)
      else if ans < buf then count t buf 0 else count t ans 0 in
  Scanf.scanf "%s\n%s\n" @@ fun c1 c2 ->
  Printf.printf "%d\n" (count (charlist_of_string (c1 ^ c2) 14 0) 0 0)