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 C# (Mono 4.6.2.0) (judge verdict: Accepted)

using System;
using System.Collections.Generic;
using System.Linq;
using System.Text;
using System.Threading.Tasks;

namespace ClassLibrary1
{
    public class ListNode
    {
        public int val;
        public ListNode next;
        public ListNode(int x) { val = x; }
    }


    public class Class1
    {
        static int[][] mtx ;
        static List<int>[] tm;
        static int n;
        static int[] results;
        static List<string> cons = new List<string>();
        static void Main(string[] args)
        {
            int n = int.Parse(Console.ReadLine());
            string[] s1 = Console.ReadLine().Split(' ');
            string[] s2 = Console.ReadLine().Split(' ');
            string[] s3 = Console.ReadLine().Split(' ');

            int[] n1 = new int[n];
            int[] n2 = new int[n];
            int[] n3 = new int[n];

            for(int i=0;i<n;i++)
            {
                n1[i] = int.Parse(s1[i]);
                n2[i] = int.Parse(s2[i]);
            }
            for (int i = 0; i < n-1; i++)
            {
                n3[i] = int.Parse(s3[i]);
            }

            var score = 0;

            int prev = -1;
            for (int i = 0; i < n; i++)
            {
                int cur = n1[i];
                score += n2[cur-1];
                if( cur == prev + 1 )
                {
                    score += n3[prev-1];
                }
                prev = cur;
            }

            Console.WriteLine(score);
        }

 

    }

}