#include <bits/stdc++.h>
using namespace std;
long long a[30], b[30], c[30];
bool vis[30];
signed main() {
  long long n;
  cin >> n;
  for (long long i = 1; i <= n; i++) cin >> a[i];
  for (long long i = 1; i <= n; i++) cin >> b[i];
  for (long long i = 1; i < n; i++) cin >> c[i];
  long long sum = 0;
  sum += b[a[1]];
  vis[a[1]] = 1;
  for (long long i = 2; i <= n; i++) {
    sum += b[a[i]];
    vis[a[i]] = 1;
    if (vis[a[i] - 1]) sum += c[a[i] - 1];
  }
  cout << sum;
  return 0;
}
