#include <bits/stdc++.h>
#pragma GCC optimize("Ofast")
using namespace std;
using ll = long long;
using ull = unsigned long long;
using pii = pair<int, int>;
using pll = pair<long long, long long>;
constexpr char ln = '\n';
constexpr long long MOD = 1000000007LL;
template <class T, class U>
inline bool chmax(T &a, U b) {
  if (a < b) {
    a = b;
    return true;
  }
  return false;
}
template <class T, class U>
inline bool chmin(T &a, U b) {
  if (a > b) {
    a = b;
    return true;
  }
  return false;
}
int main() {
  ios::sync_with_stdio(false);
  cin.tie(nullptr);
  int n;
  cin >> n;
  int 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) {
    --a[i];
    ans += b[a[i]];
    if (i > 0) {
      ans += c[a[i - 1]];
    }
  }
  cout << ans << ln;
  return 0;
}
