#include <bits/stdc++.h>
int main(void) {
  int n;
  scanf("%d", &n);
  int *a, *b, *c;
  a = (int *)malloc(sizeof(int) * (n));
  b = (int *)malloc(sizeof(int) * (n));
  c = (int *)malloc(sizeof(int) * (n));
  int i = 0;
  int j = 0;
  while (i < n) {
    scanf("%d", &a[i]);
    i++;
  }
  i = 0;
  while (i < n) {
    scanf("%d", &b[i]);
    i++;
  }
  i = 0;
  while (i < n - 1) {
    scanf("%d", &c[i]);
    i++;
  }
  i = 1;
  int st = b[a[0] - 1];
  while (i < n) {
    st += b[a[i] - 1];
    if (a[i] == a[i - 1] + 1) st += c[a[i - 1] - 1];
    printf("st:%d, i:%d, a[i]:%d\n", st, i, a[i]);
    i++;
  }
  printf("%d\n", st);
  return (0);
}
