Problem:
Score : 200 points

Problem Statement

Takahashi went to an all-you-can-eat buffet with N kinds of dishes and ate all of them (Dish 1, Dish 2, \ldots, Dish N) once.

The i-th dish (1 \leq i \leq N) he ate was Dish A_i.

When he eats Dish i (1 \leq i \leq N), he gains B_i satisfaction points.

Additionally, when he eats Dish i+1 just after eating Dish i (1 \leq i \leq N - 1), he gains C_i more satisfaction points.

Find the sum of the satisfaction points he gained.

Constraints

All values in input are integers.

2 \leq N \leq 20

1 \leq A_i \leq N

A_1, A_2, ..., A_N are all different.

1 \leq B_i \leq 50

1 \leq C_i \leq 50

Input

Input is given from Standard Input in the following format:

N
A_1 A_2 ... A_N
B_1 B_2 ... B_N
C_1 C_2 ... C_{N-1}

Output

Print the sum of the satisfaction points Takahashi gained, as an integer.

Sample Input 1

3
3 1 2
2 5 4
3 6

Sample Output 1

14

Takahashi gained 14 satisfaction points in total, as follows:

First, he ate Dish 3 and gained 4 satisfaction points.

Next, he ate Dish 1 and gained 2 satisfaction points.

Lastly, he ate Dish 2 and gained 5 + 3 = 8 satisfaction points.

Sample Input 2

4
2 3 4 1
13 5 8 24
45 9 15

Sample Output 2

74

Sample Input 3

2
1 2
50 50
50

Sample Output 3

150

Solution in OCaml (4.10.0) (judge verdict: Accepted)

let () =
  Scanf.scanf "%d\n" @@ fun n ->
  let arr = Array.init n @@ fun _ -> Scanf.scanf "%d " @@ fun a -> a in
  let brr = Array.init n @@ fun _ -> Scanf.scanf "%d " @@ fun b -> b in
  let crr = Array.init (n-1) @@ fun _ -> Scanf.scanf "%d " @@ fun c -> c in
  let ans = ref 0 in
  let bfr = ref arr.(0) in
  for i = 0 to n - 1 do
    ans := !ans + brr.(arr.(i)-1);
    if i <> 0 && arr.(i) - !bfr = 1 then ans := !ans + crr.(!bfr-1);
    bfr := arr.(i)
  done;
  Printf.printf "%d\n" !ans