#include <bits/stdc++.h>
using namespace std;
void solve(void) {
  int N;
  cin >> N;
  vector<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 res = 0;
  int prev = -1;
  for (int i = 0; i < N; ++i) {
    res += b[a[i] - 1];
    if (prev >= 0) {
      res += c[prev];
    }
    prev = a[i] - 1;
  }
  cout << res << endl;
}
int main(void) {
  solve();
  return 0;
}
