{-# LANGUAGE BangPatterns     #-}
{-# LANGUAGE TupleSections    #-}
{-# LANGUAGE TypeApplications #-}

import           Control.Monad
import           Control.Monad.State
import           Data.Bits
import qualified Data.ByteString.Char8             as BSC8
import           Data.Char
import           Data.Coerce
import qualified Data.Vector.Fusion.Stream.Monadic as VFSM
import qualified Data.Vector.Unboxed               as VU
import qualified Data.Vector.Unboxed.Mutable       as VUM

inf :: Int
inf = 1234567890
{-# INLINE inf #-}

main :: IO ()
main = do
  n <- readLn :: IO Int
  as <- seqInput n
  m <- readLn :: IO Int
  bs <- VU.reverse . bucketSort <$> seqInput m
  dp <- VUM.unsafeNew ((1 :: Int) `unsafeShiftL` n) :: IO (VUM.IOVector (Int, Int))
  VUM.unsafeWrite dp 0 (0, 0)
  forM_ [0 .. ((1 :: Int) `unsafeShiftL` n - 1)] $ \s -> forM_ [0 .. (n - 1)] $ \i -> when (s .&. ((1 :: Int) `unsafeShiftL` i) == 0) $ do
    (j, a) <- VUM.unsafeRead dp s
    if (j < m) && (a + as VU.! i <= bs VU.! j)
      then VUM.unsafeModify dp (min (j, a + as VU.! i)) (s + ((1 :: Int) `unsafeShiftL` i))
      else when ((j + 1 < m) && (as VU.! i <= bs VU.! (j + 1))) $  VUM.unsafeModify dp (min (j + 1, as VU.! i)) (s + ((1 :: Int) `unsafeShiftL` i))
  (ans, _) <- VUM.unsafeRead dp ((1 :: Int) `unsafeShiftL` n - 1)
  if ans < m
    then print $ ans + 1
    else putStrLn "-1"
  return ()


type Parser a = StateT BSC8.ByteString Maybe a
runParser :: Parser a -> BSC8.ByteString -> Maybe (a, BSC8.ByteString)
runParser = runStateT
{-# INLINE runParser #-}
int :: Parser Int
int = coerce $ BSC8.readInt . BSC8.dropWhile isSpace
{-# INLINE int #-}
seqInput :: Int -> IO (VU.Vector Int)
seqInput n = VU.unfoldrN n (runParser int) <$> BSC8.getLine
{-# INLINE seqInput #-}
rev' :: Monad m => Int -> (Int -> m ()) -> m ()
rev' n = flip VFSM.mapM_ (streamR 0 (n + 1))
{-# INLINE rev' #-}
streamR :: Monad m => Int -> Int -> VFSM.Stream m Int
streamR !l !r = VFSM.Stream step (r - 1)
  where
    step x
      | x >= l = return $ VFSM.Yield x (x - 1)
      | otherwise = return VFSM.Done
    {-# INLINE [0] step #-}
{-# INLINE [1] streamR #-}

bucketSort :: VU.Vector Int -> VU.Vector Int
bucketSort = VU.concatMap (uncurry $ flip VU.replicate) . VU.indexed . VU.unsafeAccumulate (+) (VU.replicate 21 0) . VU.map (,1)
{-# INLINE bucketSort #-}