minTurns :: Integral a => [a] -> a -> a -> a
minTurns _ 0 0 = 0
minTurns ds x y
    | m0 `elem` ds = 1
    | otherwise = max 2 $ (m0 + dmax - 1) `div` dmax
    where
        x0 = abs x
        y0 = abs y
        m0 = max x0 y0
        dmax = maximum ds

main :: IO ()
main = do
    _ <- getLine
    ds <- fmap read . words <$> getLine :: IO [Int]
    [x, y] <- fmap read . words <$> getLine :: IO [Int]
    print $ minTurns ds x y