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;
class Program
{
  static void Main(string[] args)
  {
    // 入力文字列を取得
    int n = int.Parse(Console.ReadLine());
    string[] aArrayStr = Console.ReadLine().Split(' ');
    string[] bArrayStr = Console.ReadLine().Split(' ');
    string[] cArrayStr = Console.ReadLine().Split(' ');
    
    // A列を数値に変換
    int[] aArray = new int[n];
    for (int a = 0; a < n; a++) {
      aArray[a] = int.Parse(aArrayStr[a]);
    }
    
    // B列を数値に変換
    int[] bArray = new int[n];
    for (int b = 0; b < n; b++) {
      bArray[b] = int.Parse(bArrayStr[b]);
    }
    
    // C列を数値に変換
    int[] cArray = new int[n-1];
    for (int c = 0; c < n-1; c++) {
      cArray[c] = int.Parse(cArrayStr[c]);
    }
    
    int sum = 0;
    for (int i = 0; i < n; i++)
    {
      // 満足度
      sum += bArray[aArray[i] - 1];
      
      // 追加満足度
      if ((0 < i) && (aArray[i] - 1 == aArray[i-1]))
      {
        sum += cArray[aArray[i-1]-1];
      }
    }
    Console.WriteLine(sum);
  }
}