#include <bits/stdc++.h>
using namespace std;
int main() {
  int n, i, indx, sum = 0;
  cin >> n;
  int arr1[n + 2], arr2[n + 2], arr3[n + 2];
  arr3[0] = 200000;
  for (i = 1; i <= n; i++) {
    cin >> arr1[i];
  }
  for (i = 1; i <= n; i++) {
    cin >> arr2[i];
  }
  for (i = 1; i < n; i++) {
    cin >> arr3[i];
  }
  for (i = 1; i <= n; i++) {
    indx = arr1[i];
    sum += arr2[indx];
    if (arr1[i] - arr1[i - 1] == 1) sum += arr3[indx - 1];
  }
  cout << sum << endl;
  return 0;
}
