import qualified Data.List as L

main :: IO ()
main = do
    _ <- getLine
    w <- map read . words <$> getLine
    _ <- getLine
    b <- map read . words <$> getLine
    print $ solve w b

solve :: [Int] -> [Int] -> Int
solve w b = max (solve' w' b') (solve' b' w')
    where w' = L.sort w
          b' = L.sort b

          solve' :: [Int] -> [Int] -> Int
          solve' [] _    = 0
          solve' (t:h) c = solve'' (c, h) 1 t
              where
                  solve'' :: ([Int], [Int]) -> Int -> Int -> Int
                  solve'' ([], _) n _ = n
                  solve'' (a, d) n p =
                      case dropWhile (<= p) a of
                          []    -> n
                          (g:u) -> solve'' (d, u) (n + 1) g