-- Try yukicoder
-- author: Leonardone @ NEETSDKASU

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

solve xs = ans
    where
        (zs, ys) = foldl (\(a, b) (x:y:_) -> (x : a, y : b)) ([], []) xs
        (ans, _) = foldl (\(a, b) y -> if elem y b then (a, b) else (y : a, y : b)) ([], zs) ys