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