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-1];
    int sum = 0;

    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 j = 0;

    for(int i = 0;i < n;i++){
      sum += b[a[i]-1];
      if(i == n-1) break;
      if(a[i]+1 == a[i+1]){
        sum += c[a[i]-1];
      }
    }

    System.out.println(sum);

  }

}
