#include <bits/stdc++.h>
using namespace std;
int a[25], b[25], c[25];
int main() {
  int n;
  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 - 1; i++) {
    cin >> c[i];
  }
  long long c1 = 0;
  for (int i = 1; i <= n; i++) {
    c1 = c1 + b[a[i]];
  }
  for (int i = 2; i <= n; i++) {
    if (a[i] - a[i - 1] == 1) {
      c1 = c1 + c[a[i - 1]];
    }
  }
  cout << c1 << endl;
}
