#include <bits/stdc++.h>
int n, ans;
int a[25], b[25], c[25];
int main() {
  (void)scanf("%d", &n);
  for (int i = 1; i <= n; i++) (void)scanf("%d", &a[i]);
  for (int i = 1; i <= n; i++) (void)scanf("%d", &b[i]);
  for (int i = 1; i < n; i++) (void)scanf("%d", &c[i]);
  for (int i = 1; i <= n; i++) {
    ans += b[a[i]];
    if (i > 1 && a[i] == a[i + 1] - 1) ans += c[a[i]];
  }
  printf("%d\n", ans);
  return 0;
}
