#include <bits/stdc++.h>
using namespace std;
template <class T>
using PAIR = pair<T, T>;
template <class T>
using vec = vector<T>;
template <class T>
using maps = map<string, T>;
template <class T>
using mapi = map<int, T>;
using ll = long long;
int main() {
  int N;
  cin >> N;
  vector<int> A;
  vector<int> B;
  vector<int> C;
  for (int i = 0; i < N; i++) {
    int x;
    cin >> x;
    A.push_back(x);
  }
  for (int i = 0; i < N; i++) {
    int x;
    cin >> x;
    B.push_back(x);
  }
  for (int i = 0; i < N - 1; i++) {
    int x;
    cin >> x;
    C.push_back(x);
  }
  int ans = 0;
  for (int i = 0; i < N; i++) {
    ans += B[A[i]];
    if (i != N - 1 && A[i] + 1 == A[i + 1]) {
      ans += C[A[i]] - 1;
    }
  }
  cout << ans << endl;
  return 0;
}
