{-# 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.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 -> unless (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 #-}
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 #-}