#include <bits/stdc++.h>
using namespace std;
int a[25], b[25], c[25];
int main() {
  int n, i, p = 0;
  cin >> n;
  for (i = 1; i <= n; i++) {
    cin >> a[i];
  }
  for (i = 1; i <= n; i++) {
    cin >> b[i];
    p += b[i];
  }
  for (i = 1; i < n; i++) {
    cin >> c[i];
  }
  for (i = 2; i <= n; i++) {
    if (a[i] - 1 == a[i - 1]) p += c[a[i]];
  }
  cout << p;
  return 0;
}
