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