using System;
using System.Collections.Generic;
using System.Linq;

namespace abc140_b
{
    class Program
    {
        static void Main(string[] args)
        {
            var n = int.Parse(Console.ReadLine());
            var arrayA = Console.ReadLine().Split(' ').Select(int.Parse).ToList();
            var arrayB = Console.ReadLine().Split(' ').Select(int.Parse).ToList();
            var arrayC = Console.ReadLine().Split(' ').Select(int.Parse).ToList();

            var sum = 0;
            var prev = -1;
            
            foreach (var a in arrayA)
            {
                var index = a - 1;
                var b = arrayB[index];
                var c = 0;
                if (index == prev + 1)
                {
                    c = arrayC[index - 1];
                }

                sum += b + c;
                prev = index;
            }
            
            Console.WriteLine(sum);
        }
    }
}
