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++14 (GCC 5.4.1) (judge verdict: Accepted)

#include <iostream>
#include <vector>

using namespace std;

int main() {
  int N;
  cin >> N;
  
  vector<int> vecA(N);
  for (int i = 0; i < N; i++) {
    cin >> vecA.at(i);
  }
  
  vector<int> vecB(N);
  for (int i = 0; i < N; i++) {
    cin >> vecB.at(i);
  }
  
  vector<int> vecC(N-1);
  for (int i = 0; i < N-1; i++) {
    cin >> vecC.at(i);
  }
  
  int nTh;
  int sum;
  for (int i = 0; i < N; i++) {
    nTh = vecA.at(i) - 1;
    sum += vecB.at(nTh);
    
    if (i== N-1) {continue;}
    if (vecA.at(i+1) - vecA.at(i) == 1) {
      sum += vecC.at(nTh);
    }    
  } 
  
  cout << sum <<endl;
}