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