#include <bits/stdc++.h>
using namespace std;
int main() {
  int N;
  cin >> N;
  vector<int> A;
  vector<int> B;
  vector<int> C;
  for (int i = 0; i < N; i++) {
    int x;
    cin >> x;
    A.push_back(x);
  }
  for (int i = 0; i < N; i++) {
    int x;
    cin >> x;
    B.push_back(x);
  }
  for (int i = 0; i < N - 1; i++) {
    int x;
    cin >> x;
    C.push_back(x);
  }
  int ans = 0;
  for (int i = 0; i < N; i++) {
    ans += B.at(A.at(i));
    if (i != N - 1 && A.at(i) + 1 == A.at(i + 1)) {
      ans += C.at(A.at(i));
    }
  }
  cout << ans << endl;
  return 0;
}
