#include <bits/stdc++.h>
using namespace std;
int n, ans;
int a[102], b[102], c[102], book[102];
int main() {
  scanf("%d", &n);
  for (int i = 1; i <= n; i++) scanf("%d", &a[i]);
  for (int i = 1; i <= n; i++) scanf("%d", &b[i]);
  for (int i = 1; i < n; i++) scanf("%d", &c[i]);
  for (int i = 1; i <= n; i++) {
    ans += b[a[i]];
    book[a[i]] = 1;
    if (book[a[i] - 1] == 1) ans += c[a[i] - 1];
  }
  printf("%d", ans);
  return 0;
}
