import Control.Monad
import Data.List

main = do
  n <- readLn
  ws <- replicateM n $ words <$> getLine
  putStrLn . show $ solve ws

solve :: [[String]] -> Int
solve ws = read $ head $ foldl intersect ["0","1","2","3","4","5","6","7","8","9"] ws' 
  where ws' = map check ws :: [[String]]

check :: [String] -> [String]
check xs = if e == "NO" then filter (\n -> not (elem n xs')) ["0","1","2","3","4","5","6","7","8","9"] else xs'
  where
    xs' = take 4 xs :: [String]
    e = xs !! 4 :: String