main :: IO ()
main = do
  getLine
  ds <- fmap (map read . words) getLine
  [dx, dy] <- fmap (map read . words) getLine
  let result = proc 0 ds (max dx dy)
  print result

proc :: Int -> [Int] -> Int -> Int
proc count ds dest
  | dest `elem` ds = count + 1
  | dest < (maximum ds * 2) = count + 2
  | otherwise = proc (count + 1) ds (dest - maximum ds)