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