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