#include <bits/stdc++.h>
using namespace std;
int main() {
  cin.tie(0);
  ios::sync_with_stdio(false);
  int N;
  int SUM = 0;
  cin >> N;
  vector<int> A(N);
  vector<int> B(N);
  vector<int> C(N);
  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];
  for (int i = 0; i < (N - 1); ++i) {
    if (i > 0 && A[i] + 1 == A[i + 1]) SUM += C[A[i] - 1];
  }
  cout << accumulate(B.begin(), B.end(), 0) + SUM;
  return 0;
}
