#include <bits/stdc++.h>
using namespace std;
int main() {
  int N;
  cin >> N;
  vector<int> A(N);
  for (int i = 0; i < N; i += 1) cin >> A[i];
  vector<int> B(N);
  for (int i = 0; i < N; i += 1) cin >> B[i];
  vector<int> C(N - 1);
  for (int i = 0; i < N - 1; i += 1) cin >> C[i];
  int count = 0;
  for (int i = 0; i < N; i += 1) count += B[A[i] - 1];
  for (int i = 0; i < N - 2; i += 1)
    if (A[i] + 1 == A[i + 1]) {
      count += C[A[i] - 1];
    }
  cout << count << endl;
}
