#include <bits/stdc++.h>
int main(void) {
  char str1[5], str2[100], str3[100], str4[100];
  int N, a[20], b[20], c[20], i, sum;
  fgets(str1, sizeof(str1), stdin);
  fgets(str2, sizeof(str2), stdin);
  fgets(str3, sizeof(str3), stdin);
  fgets(str4, sizeof(str4), stdin);
  N = atoi(str1);
  a[0] = atoi(strtok(str2, " "));
  for (i = 1; i < N; i++) {
    a[i] = atoi(strtok(NULL, " "));
  }
  b[0] = atoi(strtok(str3, " "));
  for (i = 1; i < N; i++) {
    b[i] = atoi(strtok(NULL, " "));
  }
  c[0] = atoi(strtok(str4, " "));
  for (i = 1; i < N - 1; i++) {
    c[i] = atoi(strtok(NULL, " "));
  }
  sum = b[a[0]];
  for (i = 1; i < N; i++) {
    sum += b[a[i]];
    if (a[i] == a[i - 1] + 1) {
      sum += c[a[i - 1]];
    }
  }
  printf("%d\n", sum);
  return 0;
}
