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