import Control.Monad
import Control.Applicative
import Data.List

main = do
  t <- readLn
  x <- map words <$> replicateM t getLine

  putStrLn . show $ solve [0..9] [0..9] (map toTuple x)

get1st (a,_,_,_,_) = a

solve :: [Int] -> [Int] -> [(Int,Int,Int,Int,String)] -> Int
solve (x:[]) _ _ = x
solve _ (x:[]) _ = x
solve ns as ((a,b,c,d,r):xs)
  | r == "NO" = solve (ns \\ [a,b,c,d]) as xs
  | r == "YES" = solve [a,b,c,d] (intersect as [a,b,c,d]) xs

toTuple :: [String] -> (Int,Int,Int,Int,String)
toTuple (a:b:c:d:e:[])  = (read a,read b,read c,read d,e)