#include <bits/stdc++.h>
using namespace std;
int main() {
  int n;
  cin >> n;
  int a[n + 1], b[n + 1], c[n + 1];
  for (int i = 1; i <= n; i++) cin >> a[i];
  for (int i = 1; i <= n; i++) cin >> b[i];
  for (int i = 1; i < n; i++) cin >> c[i];
  int sum;
  sum += b[a[0]];
  for (int i = 2; i <= n; i++) {
    sum += b[a[i]];
    if (a[i - 1] + 1 == a[i]) sum += c[(int)(a[i] - 1)];
  }
  cout << sum << endl;
  return 0;
}
