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