let () =
  let rec search (e,w) lst = 
  	match lst with
    | [] -> "NA"
    | f :: r ->
      if f = "O" && e = 2 then "East"
      else if f = "X" && w = 2 then "West"
      else if f = "O" then search (e+1,0) r
      else search (0,w+1) r in
  let s = read_line () in
  let lst = Str.split (Str.regexp "") s in
  Printf.printf "%s\n" (search (0,0) lst)