import java.util.*;

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];
    for(int i=0;i<n;i++){
      a[i] = sc.nextInt();
      a[i]--;
    }
    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]];
      if(i<n-1 &&a[i+1]==a[i]+1)ans+=c[a[i]];
    }
    System.out.println(ans);

  }
}
