#include <bits/stdc++.h>
using namespace std;
int main(void) {
  int n, i, max, id;
  cin >> n;
  int *a = new int[n];
  int *b = new int[n];
  int *c = new int[n - 1];
  for (i = 0; i < n; i++) {
    cin >> a[i];
  }
  for (i = 0; i < n; i++) {
    cin >> b[i];
  }
  for (i = 0; i < n - 1; i++) {
    cin >> c[i];
  }
  id = 0;
  max = 0;
  for (i = 0; i < n; i++) {
    id = a[i];
    max = max + b[id - 1];
    if ((i > 0) && a[i - 1] == a[i] - 1) {
      max = max + c[i - 1 - 1];
    }
  }
  cout << max << "\n";
  delete[] a;
  delete[] b;
  delete[] c;
  return 0;
}
