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