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