import Control.Monad (replicateM)

toInt x = read x :: Int

disammble s =
  (map toInt (init s), last s)

judge cand phrase =
  if snd phrase == "NO"
    then [x | x <- cand, x `notElem` fst phrase]
    else [x | x <- fst phrase, x `elem` cand]

main = do
  n <- readLn
  input <- replicateM n getLine
  let mind = map words input
  let res = foldl judge [0 .. 9] (map disammble mind)
  print $ head res