#include <bits/stdc++.h>
using namespace std;
int a[30], b[30], c[30];
int main() {
  int n;
  cin >> n;
  for (int i = 1; i <= n; i++) cin >> a[i];
  for (int i = 1; i <= n; i++) cin >> b[i];
  for (int i = 1; i < n; i++) cin >> c[i];
  int sum = 0;
  sum += b[a[1]];
  b[a[1]] = 0;
  for (int i = 2; i <= n; i++) {
    sum += b[a[i]];
    if (b[a[i] - 1] == 0) sum += c[a[i] - 1];
    b[a[i]] = 0;
  }
  cout << sum;
}
