#include <bits/stdc++.h>
int main() {
  int n;
  std::cin >> n;
  std::vector<int> a(n), b(n), c(n);
  for (int i = 0; i < n; ++i) {
    std::cin >> a[i];
    a[i]--;
  }
  for (int i = 0; i < n; ++i) std::cin >> b[i];
  for (int i = 0; i < n - 1; ++i) std::cin >> c[i];
  int sum = 0;
  for (int i = 0; i < n; ++i) sum += b[a[i]];
  for (int i = 0; i < n - 1; ++i)
    if (a[i] + 1 == a[i + 1]) sum += c[i];
  std::cout << sum << std::endl;
}
