#include <bits/stdc++.h>
int main() {
  long long int N, tmp;
  std::vector<long long int> A, B, C;
  long long int ans = 0;
  scanf("%lld", &N);
  for (long long int i = 0; i < N; i++) {
    scanf("%lld", &tmp);
    A.push_back(tmp - 1);
  }
  for (long long int i = 0; i < N; i++) {
    scanf("%lld", &tmp);
    ans += tmp;
  }
  for (long long int i = 0; i < N - 1; i++) {
    scanf("%lld", &tmp);
    C.push_back(tmp);
  }
  for (long long int i = 1; i < N; i++) {
    if (A[i] = A[i - 1] + 1) {
      ans += C[A[i - 1]];
    }
  }
  std::cout << ans << std::endl;
  return 0;
}
