#include <bits/stdc++.h>
const double PI =
    3.141592653589793238462643383279502884197169399375105820974944;
using namespace std;
long long ModExp(long long x, long long y, long long m) {
  long long res = 1;
  x = x % m;
  while (y > 0) {
    if (y & 1) res = (res * x) % m;
    y = y >> 1;
    x = (x * x) % m;
  }
  return res;
}
void solve() {
  long long n;
  cin >> n;
  long long a[n];
  long long b[n];
  long long c[n];
  for (long long i = 0; i < n; i++) {
    cin >> a[i];
  }
  for (long long i = 0; i < n; i++) {
    cin >> b[i];
  }
  for (long long i = 0; i < n - 1; i++) {
    cin >> c[i];
  }
  long long ans = b[a[0] - 1];
  for (long long i = 1; i < n; i++) {
    if (a[i] >= 2) {
      ans += c[a[i] - 1 - 1];
    }
    ans += b[a[i] - 1];
  }
  cout << ans << endl;
}
signed main() {
  ios_base::sync_with_stdio(false);
  cin.tie(0);
  cout.tie(0);
  ;
  long long t = 1;
  while (t--) {
    solve();
  }
}
