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