#include <bits/stdc++.h>
using namespace std;
const int N = 100;
int n, res;
int a[N], b[N], c[N];
int main() {
  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];
  for (int i = 1; i <= n; i++) {
    res += b[a[i]];
    if (i > 1) res += c[a[i] - 1];
  }
  cout << res << endl;
  return 0;
}
