using System;
using System.Linq;
using System.Collections.Generic;
using static System.Math;
using static System.Console;
using System.Text;

class Program
{
    static void Main(string[] args)
    {
        solve();
    }
    static Scanner cin;
    static int N;
    static int[] A, B, C;

    static void input()
    {
        cin = new Scanner();
        N = cin.nextInt();
        A = ReadLine().Split(" ").Select(int.Parse).Select(x => x - 1).ToArray();
        B = cin.ArrayInt(N);
        C = cin.ArrayInt(N - 1);
    }
    static void solve()
    {
        input();

        int ans = 0;

        for (int i = 0; i < N - 1; i++)
        {
            ans += B[A[i]];
            if (A[i] == A[i + 1] - 1)
                ans += C[A[i]];
        }
        ans += B[A[N - 1]];
        WriteLine(ans);
    }
    class Scanner
    {
        string[] s;
        int i;

        char[] cs = new char[] { ' ' };

        public Scanner()
        {
            s = new string[0];
            i = 0;
        }
        
        public string next()
        {
            if (i < s.Length) return s[i++];
            string st = Console.ReadLine();
            while (st == "") st = Console.ReadLine();
            s = st.Split(cs, StringSplitOptions.RemoveEmptyEntries);
            if (s.Length == 0) return next();
            i = 0;
            return s[i++];
        }

        public int nextInt()
        {
            return int.Parse(next());
        }

        public int[] ArrayInt(int N, int add = 0)
        {
            int[] Array = new int[N];
            for(int i = 0; i < N; i++)
            {
                Array[i] = nextInt() + add;
            }
            return Array;
        }

        public long nextLong()
        {
            return long.Parse(next());
        }

        public long[] ArrayLong(int N, long add = 0)
        {
            long[] Array = new long[N];
            for(int i = 0; i < N; i++)
            {
                Array[i] = nextLong() + add;
            }
            return Array;
        }

        public double nextDouble()
        {
            return double.Parse(next());
        }

        public double[] ArrayDounble(int N, int add = 0)
        {
            double[] Array = new double[N];
            for (int i = 0; i < N; i++)
            {
                Array[i] = nextDouble() + add;
            }
            return Array;
        }
    }
}