#include <bits/stdc++.h>
using namespace std;
int main() {
  int n;
  cin >> n;
  int a[25];
  int b[25];
  int c[24];
  int sum = 0;
  int count = 0;
  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 - 1; i++) {
    cin >> c[i];
  }
  for (int j = 1; j <= n; j++) {
    sum = sum + b[a[j]];
    if (j != 1 && a[j] - 1 == a[j - 1]) {
      count++;
      sum = sum + c[count];
    }
  }
  cout << sum << endl;
  return 0;
}
