using System;
using System.Collections;
using System.Collections.Generic;
class Program
{
    static void Main(string[] args)
    {
        int n = int.Parse(Console.ReadLine());
        int[] a = new int[n];
        int[] b = new int[n];
        int[] c = new int[n - 1];

        string[] s = Console.ReadLine().Split();
        for (int i = 0; i < n; i++)
        {
            a[i] = int.Parse(s[i].ToString());
        }
        s = Console.ReadLine().Split();
        for (int i = 0; i < n; i++)
        {
            b[i] = int.Parse(s[i].ToString());
        }
        s = Console.ReadLine().Split();
        for (int i = 0; i < n - 1; i++)
        {
            c[i] = int.Parse(s[i].ToString());
        }


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