-- Try yukicoder
-- author: Leonardone @ NEETSDKASU

import qualified Data.Set as S

main = interact $ unlines . solve . map words . tail . lines

solve xs = ans []
    where
        hm = S.fromList $ map (!! 0) xs
        ys = map (!! 1) xs
        (ans, _) = foldl f (id, hm) ys
        f (g, s) y =
            if S.member y s
                then (g, s)
                else (g.(y:), S.insert y s)