let () =
  let x, y = Scanf.scanf "%s %s " (fun x y -> x, y) in
  let s = x ^ y in
  let n = String.length s in
  let rec doit i cnt m =
    if i = n then m
    else if s.[i] = 'x' then doit (i + 1) 0 m
    else
      let cnt = cnt + 1 in
      doit (i + 1) cnt (max m cnt) in
  doit 0 0 0 |> Printf.printf "%d\n"