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