import Data.List (intersect, (\\))

parseAnswer :: [String] -> [String] -> [String]
parseAnswer cds (a : b : c : d : yn : _)
    | yn == "YES" = intersect [a, b, c, d] cds
    | otherwise   = cds \\ [a, b, c, d]

main :: IO ()
main = do
    let c0s = map (show :: Int -> String) [0 .. 9]
    _ <- getLine
    putStrLn . head . foldl parseAnswer c0s . map words . lines =<< getContents