#include <bits/stdc++.h>
using namespace std;
int main() {
  int n;
  cin >> n;
  vector<int> A(n), B(n), C(n - 1);
  for (auto &a : A) {
    cin >> a;
  }
  for (auto &b : B) {
    cin >> b;
  }
  for (auto &c : C) {
    cin >> c;
  }
  int res = 0;
  for (int i = 0; i < n - 1; i++) {
    res = res + B[i];
    if ((A[i] + 1) == (A[i + 1])) {
      res = res + C[A[i] + 1];
    }
  }
  res = res - B.back();
  cout << res;
  return 0;
}
