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