#include <bits/stdc++.h>
using namespace std;
using ll = long long;
const ll M = 1000000007;
const ll M1 = 998244353;
using vl = vector<ll>;
using pll = pair<ll, ll>;
ll power(ll x, ll y) {
  if (y == 0) return 1;
  ll res = power(x, y / 2);
  res = (res * res);
  if (y & 1) res = (res * x);
  return res;
}
ll powermod(ll x, ll y, ll mod) {
  if (y == 0) return 1;
  ll res = powermod(x, y / 2, mod);
  res = (res * res) % mod;
  if (y & 1) res = (res * x) % mod;
  return res;
}
void solve() {
  int n;
  cin >> n;
  int a[n + 1], b[n + 1];
  for (int i = 1; i <= n; i++) cin >> a[i];
  for (int i = 1; i <= n; i++) cin >> b[i];
  int c[n];
  for (int i = 1; i < n; i++) cin >> c[i];
  int ans = 0;
  for (int i = 1; i <= n; i++) {
    ans += b[a[i]];
    if (a[i] - a[i - 1] == 1) ans += c[a[i - 1]];
  }
  cout << ans << "\n";
}
int main() {
  ios_base::sync_with_stdio(false);
  cin.tie(NULL);
  int t = 1;
  for (int i = 1; i <= t; i++) {
    solve();
  }
  return 0;
}
