matrixRow :: Integer -> Matrix -> (Integer, Integer)
matrixRow n m
    | n == 0 = fst m
    | n == 1 = snd m
    | otherwise = error $ show n ++ " out of row num"
matrixRow :: Integer -> Matrix -> (Integer, Integer)
matrixRow n m
    | n == 0 = fst m
    | n == 1 = snd m
    | otherwise = error $ show n ++ " out of row num"
matrixRow n m
    | n == 0 = fst m
    | n == 1 = snd m
    | otherwise = error $ show n ++ " out of row num"