#include <bits/stdc++.h>
using namespace std;
using pair = pair<int64_t, int64_t>;
using tup = tuple<int64_t, int64_t, int64_t>;
using vec = vector<int64_t>;
using vvec = vector<vec>;
signed main() {
  ios::sync_with_stdio(false);
  cin.tie(0);
  int64_t N;
  cin >> N;
  vec A(N + 1), B(N + 1), C(N + 1);
  for (int64_t i = 0; i < N; i++) cin >> A.at(i);
  for (int64_t i = 0; i < N; i++) cin >> B.at(i);
  for (int64_t i = 0; i < N - 1; i++) cin >> C.at(i);
  int64_t ans = 0;
  for (int64_t i = 0; i < N; i++) {
    if (i == 0) {
      ans += B.at(A.at(i));
    } else if (i >= 1) {
      if (A.at(i) == A.at(i - 1) - 1) {
        ans += B.at(A.at(i)) + C.at(A.at(i - 1));
      } else {
        ans += B.at(A.at(i));
      }
    }
  }
  cout << ans << endl;
  return 0;
}
