#include <bits/stdc++.h>
using namespace std;
const int mod = 1000000007;
const int inf = (int)1e9 + 7;
const long long INF = 1LL << 60;
using ll = long long;
using vi = vector<int>;
using vd = vector<double>;
using vb = vector<bool>;
using vl = vector<ll>;
using vs = vector<string>;
using vvi = vector<vector<int> >;
using vii = vector<pair<int, int> >;
template <class T>
inline bool chmin(T& a, T b) {
  if (a > b) {
    a = b;
    return true;
  }
  return false;
}
template <class T>
inline bool chmax(T& a, T b) {
  if (a < b) {
    a = b;
    return true;
  }
  return false;
}
ll GCD(ll a, ll b) { return b ? GCD(b, a % b) : a; }
int round_int(int a, int b) { return (a + (b - 1)) / b; }
int dx[8] = {1, 0, -1, 0, 1, -1, -1, 1};
int dy[8] = {0, 1, 0, -1, 1, 1, -1, -1};
constexpr auto MAX = 100010;
int main() {
  int n;
  cin >> n;
  vi a(n), b(n), c(n - 1);
  for (int i = 0; i < n; i++) cin >> a[i];
  for (int i = 0; i < n; i++) cin >> b[i];
  for (int i = 0; i < n - 1; i++) cin >> c[i];
  int ans = 0;
  for (int i = 0; i < n; i++) {
    ans += b[a[i] - 1];
    if (i != 0) {
      if (a[i - 1] < a[i]) ans += c[a[i - 1] - 1];
    }
  }
  cout << ans << endl;
}
