#include <bits/stdc++.h>
int main(void) {
  int number;
  int array[20], barray[20], carray[19];
  int sum = 0;
  scanf("%d", &number);
  for (int i = 0; i < number; i++) {
    scanf("%d", &array[i]);
  }
  for (int i = 0; i < number; i++) {
    scanf("%d", &barray[i]);
  }
  for (int i = 0; i < number - 1; i++) {
    scanf("%d", &carray[i]);
  }
  for (int i = 0; i < number; i++) {
    sum += barray[array[i] - 1];
    if ((array[i] == array[i - 1] + 1) && (i != 0)) {
      sum += carray[i - 2];
    }
  }
  printf("%d", sum);
  return 0;
}
