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