using System;
using System.Collections.Generic;
using static System.Math;
using System.Linq;
using System.Text;
 
class DandA {
    static void Main(string[] args) {
        int n = ReadLineInt();
        int[] aList = ReadLineIntArray();
        int[] bList = ReadLineIntArray();
        int[] cList = ReadLineIntArray();
        int rtn = 0;
        int wk = -10;
        for (int i = 0; i < n; i++) {
            rtn += bList[aList[i]];
            if (wk == aList[i] - 1) {
              rtn += cList[aList[i] - 1];
            }
            wk = aList[i];
        }
        Console.WriteLine(rtn);
    }
 
    static string Alphabet = "ABCDEFGHIJKLMNOPQRSTUVWXYZABCDEFGHIJKLMNOPQRSTUVWXYZ";
    static string[] strAry = new string[] {"L", "R", "U", "D"}; 
  
    static private string ReadLineStr() {return Console.ReadLine();}
    static private int ReadLineInt() {return int.Parse(Console.ReadLine());}
    static private long ReadLineLong() {return long.Parse(Console.ReadLine());}
    static private double ReadLineDouble() {return double.Parse(Console.ReadLine());}
    static private string[] ReadLineStrArray() {return Console.ReadLine().Trim().Split();}
    static private int[] ReadLineIntArray() {return Console.ReadLine().Trim().Split().Select(a => int.Parse(a)).ToArray();}
    static private long[] ReadLineLongArray() {return Console.ReadLine().Trim().Split().Select(a => long.Parse(a)).ToArray();}
    static private double[] ReadLineDoubleArray() {return Console.ReadLine().Trim().Split().Select(a => double.Parse(a)).ToArray();}
    static private decimal[] ReadLineDecimalArray() {return Console.ReadLine().Trim().Split().Select(a => decimal.Parse(a)).ToArray();}
    static private string[][] ReadMLineStrArray(int arg) { return new int[arg].Select(_ => Console.ReadLine().Split()).ToArray();}
    static private int[][] ReadMLineIntArray(int arg) { return new int[arg].Select(_ => Console.ReadLine().Split().Select(int.Parse).ToArray()).ToArray();}
 
    static private bool IsPrime(int num) {
        if (num < 2) return false;
        if (num == 2) return true;
        else if (num % 2 == 0) return false;
        double sqrtNum = Math.Sqrt(num);
        for (int i = 3; i <= sqrtNum; i += 2) {
            if (num % i == 0) return false;
        }
        return true;
    }
}