#include <bits/stdc++.h>
using namespace std;
int main() {
  int N;
  cin >> N;
  vector<int> food(N);
  for (int i = 0; i < N; i++) cin >> food[i];
  vector<int> sat(N);
  for (int i = 0; i < N; i++) cin >> sat[i];
  vector<int> C(N - 1);
  for (int i = 0; i < N - 1; i++) cin >> C[i];
  int S = 0;
  for (int i = 0; i < N; i++) {
    S += sat[food[i] - 1];
    if (i != 0 && food[i] == food[i - 1] + 1) S += C[i - 1];
  }
  cout << S << endl;
}
