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