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