using System;
using System.Linq;

namespace AtCoder
{
    class Program
    {
        static void Main(string[] args)
        {
            int number = int.Parse(Console.ReadLine());
            int[] cuisine = Console.ReadLine().Split().Select(int.Parse).ToArray();
            int[] satisfaction = Console.ReadLine().Split().Select(int.Parse).ToArray();
            int[] bonus = Console.ReadLine().Split().Select(int.Parse).ToArray();
            int result = 0;
            int beforeCuisine = -1;

            for(int i = 1;i <= number;++i)
            {
                int currentCuisine = cuisine[i - 1];

                result += satisfaction[currentCuisine - 1];

                if (currentCuisine + 1 == beforeCuisine)
                {
                    result += bonus[currentCuisine - 1];
                }

                beforeCuisine = currentCuisine;
            }

            Console.WriteLine(result.ToString());
        }
    }
}
