import java.util.*;

public class Main
{
  public static void main(String[] args)
  {
    Scanner sc = new Scanner(System.in);
    int n = sc.nextInt();
    int a[] = new int[n];
    int b[] = new int[n];
    int c[] = new int[n];
    for(int i = 0; i < n; ++i)
    {
      a[i] = sc.nextInt();
    }
    for(int i = 0; i < n; ++i)
    {
      b[i] = sc.nextInt();
    }
    for(int i = 0; i < n-1; ++i)
    {
      c[i] = sc.nextInt();
    }
    int ans = 0;
    for(int i = 0; i < n; ++i)
    {
      ans += b[a[i] - 1];
      if(i > 0 && a[i] == a[i-1] + 1)
        ans += c[a[i-1]-1];
    }

    System.out.println(ans);
  }

}
