#include <bits/stdc++.h>
using namespace std;
inline int toInt(string s) {
  int v;
  istringstream sin(s);
  sin >> v;
  return v;
}
template <class T>
inline string toString(T x) {
  ostringstream sout;
  sout << x;
  return sout.str();
}
template <class T>
inline T sqr(T x) {
  return x * x;
}
const double EPS = 1e-10;
const double PI = acos(-1.0);
int main() {
  int n;
  cin >> n;
  auto orders = vector<int>();
  for (int i = (0); i < (n); ++i) {
    int order;
    cin >> order;
    orders.push_back(order);
  }
  int answer = 0;
  for (int i = (0); i < (n); ++i) {
    int manzoku;
    cin >> manzoku;
    answer += manzoku;
  }
  auto mariajus = vector<int>();
  for (int i = (0); i < (n - 1); ++i) {
    int mariaju;
    cin >> mariaju;
    mariajus.push_back(mariaju);
  }
  for (int i = (0); i < (n); ++i) {
    if (orders[i] + 1 == orders[i + 1]) {
      answer += mariajus[orders[i]];
    } else {
    }
  }
  cout << answer << endl;
}
