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