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