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++ (GCC 9.2.1) (judge verdict: Accepted)

#include <iostream>
#include <vector>
#include <iterator>
#include <algorithm>
#include <string>
#include <map>
#include <list>
using namespace std;

// int main() {
//   int n;
//   cin >> n;
//   int a[n],b[n],c[n];
//   for(int i = 0; i < n; ++i){
//     cin >> a[i];
//   }
//   for(int i = 0; i < n; ++i){
//     cin >> b[i];
//   }
//   for(int i = 0; i < n-1; ++i){
//     cin >> c[i];
//   }
//   int res=0;
//   for(int i = 0; i < n; ++i){
//     res+=b[a[i]-1];
//     if(a[i]!=n){
//       if(b[a[i]-1] + 1 == b[a[i+1]]-1){
//         res+=c[a[i]-1];
//       }
//     }
//   }
//   cout << res << endl;
// }

int main() {
  int N; cin >> N;
  // input
  vector<int> A(N);
  for (int i = 0; i < N; ++i) {
    cin >> A[i];
    --A[i];
  }
  vector<int> B(N);
  for (int i = 0; i < N; ++i) {
    cin >> B[i];
  }
  vector<int> C(N-1);
  for (int i = 0; i < N; ++i) {
    cin >> C[i];
  }
  // calc
  int ans = 0;
  for (int i = 0; i < N; ++i) {
    ans += B[A[i]];
    if (i > 0 && A[i] == A[i-1]+1) {
      ans += C[A[i-1]];
    }
  }
  // output
  cout << ans << endl;
}