#include <bits/stdc++.h>
using namespace std;
const int maxn = 1e6 + 10;
int main() {
  int n, a[100] = {0}, b[100] = {0}, c[100] = {0}, sum = 0;
  scanf("%d", &n);
  for (int i = 0; i < n; i++) scanf("%d", &a[i]);
  for (int i = 1; i <= n; i++) scanf("%d", &b[i]);
  for (int i = 1; i <= n - 1; i++) scanf("%d", &c[i]);
  sum += b[a[0]];
  for (int i = 1; i < n; i++) {
    sum += b[a[i]] + c[a[i - 1]];
  }
  cout << sum << endl;
}
