#include <bits/stdc++.h>
using namespace std;
int main() {
  long long n;
  long long a[20], b[20], c[20];
  cin >> n;
  for (long long i = 0; i < n; i++) {
    long long x;
    cin >> x;
    x--;
    a[i] = x;
  }
  for (long long i = 0; i < n; i++) {
    cin >> b[i];
  }
  for (long long i = 0; i < n - 1; i++) {
    cin >> c[i];
  }
  long long ans = 0;
  for (long long i = 0; i < n; i++) {
    long long now = a[i];
    ans += b[now];
    if (now != n - 1) {
      long long next = a[i + 1];
      if (next == now + 1) {
        ans += c[now];
      }
    }
  }
  cout << ans;
  return 0;
}
