Problem:
Score : 200 points

Problem Statement

Takahashi went to an all-you-can-eat buffet with N kinds of dishes and ate all of them (Dish 1, Dish 2, \ldots, Dish N) once.

The i-th dish (1 \leq i \leq N) he ate was Dish A_i.

When he eats Dish i (1 \leq i \leq N), he gains B_i satisfaction points.

Additionally, when he eats Dish i+1 just after eating Dish i (1 \leq i \leq N - 1), he gains C_i more satisfaction points.

Find the sum of the satisfaction points he gained.

Constraints

All values in input are integers.

2 \leq N \leq 20

1 \leq A_i \leq N

A_1, A_2, ..., A_N are all different.

1 \leq B_i \leq 50

1 \leq C_i \leq 50

Input

Input is given from Standard Input in the following format:

N
A_1 A_2 ... A_N
B_1 B_2 ... B_N
C_1 C_2 ... C_{N-1}

Output

Print the sum of the satisfaction points Takahashi gained, as an integer.

Sample Input 1

3
3 1 2
2 5 4
3 6

Sample Output 1

14

Takahashi gained 14 satisfaction points in total, as follows:

First, he ate Dish 3 and gained 4 satisfaction points.

Next, he ate Dish 1 and gained 2 satisfaction points.

Lastly, he ate Dish 2 and gained 5 + 3 = 8 satisfaction points.

Sample Input 2

4
2 3 4 1
13 5 8 24
45 9 15

Sample Output 2

74

Sample Input 3

2
1 2
50 50
50

Sample Output 3

150

Solution in C# (Mono 4.6.2.0) (judge verdict: Accepted)

using System;
using System.IO;
using System.Linq;
using System.Text;
using System.Diagnostics;
using System.Collections;
using System.Collections.Generic;

namespace atcoder
{
    class Solver
    {
        //Solve
        public void Solve()
        {
            cin = new Scanner();
            int n = cin.nextint;

            int[] a = cin.scanint;
            int[] b = cin.scanint;
            int[] c = cin.scanint;


            int s = 0;
            int tmp = -1;
            for (int i = 0; i < n; i++)
            {
                s = s + b[a[i] - 1];
                if (a[i] - 1 == tmp)
                {
                    s = s + c[a[i] - 2];
                }
                tmp = a[i];
            }
            Console.WriteLine(s);
        }


        //Main
        public Solver() { }
        Scanner cin;
        public static int Main()
        {
            var sw = new StreamWriter(Console.OpenStandardOutput()) { AutoFlush = false };
            Console.SetOut(sw);
            new Solver().Solve();
            Console.Out.Flush();
            return 0;
        }

        //Util
        static bool IsOdd(long num) { return (num & 1) == 1; }
        static bool IsEven(long num) { return (num & 1) == 0; }
        static long GCD(long a, long b) { return b != 0 ? GCD(b, a % b) : a; }
    }

    class Scanner
    {
        string[] s; int i;
        readonly char[] cs = new char[] { ' ' };
        public Scanner() { s = new string[0]; i = 0; }
        public string[] scan => Console.ReadLine().Split();
        public int[] scanint => Array.ConvertAll(scan, int.Parse);
        public long[] scanlong => Array.ConvertAll(scan, long.Parse);
        public double[] scandouble => Array.ConvertAll(scan, double.Parse);
        public string next
        {
            get
            {
                if (i < s.Length) return s[i++];
                string st = Console.ReadLine();
                while (st == "") st = Console.ReadLine();
                s = st.Split(cs, StringSplitOptions.RemoveEmptyEntries);
                i = 0;
                return next;
            }
        }
        public int nextint => int.Parse(next);
        public long nextlong => long.Parse(next);
        public double nextdouble => double.Parse(next);
    }

    class Node<T>
    {
        private int m_height;
        private Node<T> m_parent;
        public T Item { get; private set; }
        public Node(T item)
        {
            m_height = 0;
            m_parent = this;
            Item = item;
        }
        public Node<T> Find()
        {
            if (m_parent == this) { return this; }

            Node<T> parent = m_parent.Find();
            m_parent = parent;
            return parent;
        }
        public static void Unite(Node<T> a, Node<T> b)
        {
            Node<T> p = a.Find();
            Node<T> q = b.Find();
            if (p.m_height < q.m_height)
            {
                p.m_parent = q;
                q.m_height = Math.Max(p.m_height + 1, q.m_height);
            }
            else
            {
                q.m_parent = p;
                p.m_height = Math.Max(q.m_height + 1, p.m_height);
            }
        }
    }
}