#include <bits/stdc++.h>
using namespace std;
int main() {
  int n, a[20], b[20], c[20], count = 0;
  cin >> n;
  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) {
    count += b[a[i]];
    if (a[i] + 1 == a[i + 1]) count += c[i];
  }
  cout << count << endl;
}
