main :: IO ()
main = do
  input <- getLine
  putStrLn $ check input

check :: String -> String
check []       = "NA"
check (_:[])   = "NA"
check (_:_:[]) = "NA"
check (x:y:zs)
  | x == 'O' && y == 'O' && head zs == 'O' = "East"
  | x == 'X' && y == 'X' && head zs == 'X' = "West"
  | otherwise = check (y:zs)