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