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 Java8 (OpenJDK 1.8.0) (judge verdict: Accepted)

import java.io.BufferedReader;
import java.io.InputStreamReader;
import java.util.StringTokenizer;

class Main {
        public static void main(String[] args) throws Exception {
                BufferedReader br = new BufferedReader(new InputStreamReader(System.in));
                StringTokenizer st;
                int n = Integer.parseInt(br.readLine());

                int a[] = new int[n];
                st = new StringTokenizer(br.readLine());
                for(int i=0 ; i<n ; i++) {
                        a[i] = Integer.parseInt(st.nextToken());
                }

                int b[] = new int[n];
                st = new StringTokenizer(br.readLine());
                for(int i=0 ; i<n ; i++) {
                        b[i] = Integer.parseInt(st.nextToken());
                }

                int c[] = new int[n];
                st = new StringTokenizer(br.readLine());
                for(int i=0 ; i<n-1 ; i++) {
                        c[i] = Integer.parseInt(st.nextToken());
                }

                long sum = b[a[0]-1];
                int last = a[0];
                for(int i=1 ; i<n ; i++) {
                        int x = a[i];
                        if(x == last+1) {
                                sum += c[x-2];
                        }
                        sum += b[x-1];
                        last = x;
                }

                System.out.println(sum);
        }
}