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