#include <bits/stdc++.h>
using namespace std;
int main() {
  int n;
  cin >> n;
  int a[n], b[n], c[n - 1];
  int manzoku = 0;
  for (int i = 0; i < (n); ++i) {
    cin >> a[i];
    a[i]--;
  }
  for (int i = 0; i < (n); ++i) {
    cin >> b[i];
  }
  for (int i = 0; i < (n - 1); ++i) {
    cin >> c[i];
  }
  for (int i = 0; i < (n); ++i) {
    manzoku += b[a[i]];
    int j = a[i - 1] + 1;
    if (a[i] == j) {
      manzoku += c[a[i - 1]];
    }
  }
  cout << manzoku << endl;
}
