#include <bits/stdc++.h>
using namespace std;
const long long MOD = 1000000007;
const long long INF = 1LL << 60;
signed main() {
  ios::sync_with_stdio(false);
  cin.tie(nullptr);
  long long n;
  cin >> n;
  vector<long long> a(n), b(n), c(n - 1);
  for (long long i = 0; i < (long long)(n); i++) cin >> a[i];
  for (long long i = 0; i < (long long)(n); i++) cin >> b[i];
  for (long long i = 0; i < (long long)(n - 1); i++) cin >> c[i];
  long long ans = 0;
  ans += b[0];
  for (long long i = 1; i < n; i++) {
    if (a[i] - a[i - 1] == 1) {
      ans += b[i] + c[a[i]];
    } else {
      ans += b[i];
    }
  }
  cout << ans << endl;
  return 0;
}
