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