#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 - 1);
  for (int i = 0; i < N; i++) {
    cin >> A.at(i);
  }
  for (int i = 0; i < N; i++) {
    cin >> B.at(i);
  }
  for (int i = 0; i < N - 1; i++) {
    cin >> C.at(i);
  }
  int a;
  a = -1;
  int b;
  b = 0;
  int c;
  c = -1;
  for (int i = 0; i < N; i++) {
    a = a + 1;
    b = b + B.at(A.at(a) - 1);
    if (c + 1 == B.at(A.at(a) - 1)) {
      b = b + C.at(c);
    }
    c = b + B.at(A.at(a) - 1);
  }
  cout << b << endl;
}
