#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 = 1; i <= N; i++) {
    cin >> A[i];
  }
  for (int i = 1; i <= N; i++) {
    cin >> B[i];
  }
  for (int i = 1; i <= N - 1; i++) {
    cin >> C[i];
  }
  int sum = 0;
  for (int i = 1; i <= N; i++) {
    if (A[i] = A[i - 1] + 1) {
      sum += C[i - 1];
    } else {
      sum += B[A[i]];
    }
  }
  cout << sum << endl;
}
