#include <bits/stdc++.h>
using namespace std;
int a[22], b[22], c[22];
int main() {
  ios_base::sync_with_stdio(0);
  int n;
  cin >> n;
  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 res = 0;
  for (int i = 0; i < n; i++) {
    res += b[a[i]];
    cerr << a[i] << endl;
    if (i != 0 && a[i] - a[i - 1] == 1) res += c[a[i - 1]];
  }
  cout << res;
}
