#include <bits/stdc++.h>
using namespace std;
int main() {
  int n;
  cin >> n;
  int arr[n];
  for (int i = 0; i < n; i++) cin >> arr[i];
  int arr1[n];
  int sum = 0;
  for (int i = 0; i < n; i++) {
    cin >> arr1[i];
    sum += arr1[i];
  }
  int value = n - 1;
  int arr2[value];
  for (int i = 0; i < value; i++) cin >> arr2[i];
  int tmp = 0;
  for (int i = 0; i < n; i++) {
    if (i != 0 && abs(arr[i] - arr[i - 1]) == 1) sum += arr2[arr[i - 1] - 1];
  }
  cout << sum << endl;
  return 0;
}
