#include <bits/stdc++.h>
using namespace std;
static const int giga = pow(10, 9);
int main(void) {
  int n;
  cin >> n;
  vector<int> a(n), b(n), c(n - 1);
  for (int i = 0; i < n; i++) {
    int temp;
    cin >> temp;
    a[i] = temp;
  }
  for (int i = 0; i < n; i++) {
    int temp;
    cin >> temp;
    b[i] = temp;
  }
  for (int i = 0; i < n - 1; i++) {
    int temp;
    cin >> temp;
    c[i] = temp;
  }
  int ans = 0;
  for (int i = 0; i < n; i++) {
    ans += b[a[i]];
    if (i >= 1 && a[i - 1] + 1 == a[i]) {
      ans += c[a[i]];
    }
  }
  cout << ans << endl;
  return 0;
}
