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