#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 sum = 0;
  int lastIdx = 0;
  for (int i = 0; i < n; i++) {
    sum += b[a[i] - 1];
    if (i == 0) {
      lastIdx = a[i] - 1;
      continue;
    }
    if ((a[i - 1] - 1) == lastIdx) {
      sum += c[lastIdx];
    }
    lastIdx = a[i] - 1;
  }
  cout << sum << endl;
  return 0;
}
