#include <bits/stdc++.h>
using namespace std;
int id[22], b[22], c[22];
int main() {
  int n;
  cin >> n;
  for (int i = 1; i <= n; i++) cin >> id[i];
  for (int i = 1; i <= n; i++) cin >> b[i];
  for (int i = 1; i < n; i++) cin >> c[i];
  int total = 0;
  for (int i = 1; i <= n; i++) {
    total += b[id[i]];
    if (id[i] > 1 and id[i] < n) total += c[id[i] - 1];
  }
  printf("%d\n", total);
  return 0;
}
