#include <bits/stdc++.h>
using namespace std;
int main() {
  int n;
  vector<int> a;
  vector<int> b;
  vector<int> c;
  int tmp;
  cin >> n;
  int total = 0;
  for (int i = 0; i < n; i++) {
    cin >> tmp;
    a.push_back(tmp);
  }
  for (int i = 0; i < n; i++) {
    cin >> tmp;
    b.push_back(tmp);
  }
  for (int i = 0; i < n - 1; i++) {
    cin >> tmp;
    c.push_back(tmp);
  }
  for (int i = 0; i < n; i++) {
    total += b[a[i] - 1];
    if (i > 0 && a[i - 1] != n && a[i] > 1) {
      total += c[a[i] - 2];
    }
  }
  cout << total << endl;
}
