solve :: Int -> [Int] -> [Int] -> [Int] -> Int
solve n lst_a lst_b lst_c =
  sum [lst_b !! x | x <- lst_a] +
  sum [lst_c !! x | (x, y) <- zip lst_a (tail lst_a), x + 1 == y]

main :: IO()
main = do
  cont <- getContents
  let [line1, line2, line3, line4] = lines cont
      [s_n] = words line1
      n = read s_n
      s_lst_a = words line2
      s_lst_b = words line3
      s_lst_c = words line4
      lst_a = map read s_lst_a
      lst_b = map read s_lst_b
      lst_c = map read s_lst_c
      answer = solve n lst_a lst_b lst_c
  putStrLn (show answer)
