#include <bits/stdc++.h>
using namespace std;
int main() {
  int N;
  cin >> N;
  int A[30];
  int B[30];
  int C[30];
  int sum;
  int tmp;
  int k;
  sum = 0;
  tmp = 0;
  k = 0;
  for (int i = 0; i < N; i++) {
    cin >> A[i];
  }
  for (int i = 0; i < N; i++) {
    cin >> B[i];
    sum = sum + B[i];
  }
  for (int i = 0; i < N - 1; i++) {
    cin >> C[i];
  }
  for (int i = 1; i < N; i++) {
    k = abs(A[i] - A[i - 1]);
    if (k == 1) {
      tmp = tmp + C[A[i - 1] - 1];
    }
  }
  cout << sum + tmp << endl;
  return 0;
}
