(def n (read-line))
(def a (map #(Long/parseLong %) (.split (read-line) " ")))
(def b (map #(Long/parseLong %) (.split (read-line) " ")))
(def c (map #(Long/parseLong %) (.split (read-line) " ")))

(def s1 (reduce + b))
(def s2
  (->> (map #(- %1 %2) (rest a) a)
       (map #(if (= %2 1) %1 0) a)
       (filter #(not= % 0))
       (map #(nth c (dec %)))
       (reduce +)))
(println (+ s1 s2))