#include <bits/stdc++.h>
using namespace std;
using pii = pair<int, int>;
using pli = pair<long long, int>;
using pll = pair<long long, long long>;
const long double PI = (acos(-1));
const long double EPS = 0.0000000001;
const int INF = 0x3f3f3f3f;
const int maxn = 110000;
void run_case() {
  int n;
  cin >> n;
  vector<int> a(n + 1), b(n + 1), c(n + 1), vis(55);
  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 - 1; i++) cin >> c[i];
  int ans = 0;
  for (int i = 1; i <= n; i++) {
    int cur = a[i];
    if (vis[cur - 1]) {
      ans += b[cur] + c[cur - 1];
    } else {
      ans += b[cur];
    }
    vis[cur] = 1;
  }
  cout << ans << "\n";
}
int main() {
  ios::sync_with_stdio(false);
  cin.tie(0);
  cout << setiosflags(ios::fixed) << setprecision(12);
  run_case();
  cout.flush();
  return 0;
}
