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

namespace ConsoleApp1
{
    class Program
    {
        static void Main(string[] args)
        {
            A();
        }

        static void A()
        {
            var N = ReadInt();
            var A = ReadSplitInt();
            var B = ReadSplitInt();
            var C = ReadSplitInt();

            var dict = new Dictionary<int, int>();
            for (int i = 1; i <= A.Count; i++)
                dict.Add(i, B[i - 1]);

            var sum = 0;
            for (int i = 0; i < A.Count; i++)
            {
                sum += dict[A[i]];
                if (i > 0 && A[i-1] + 1 == A[i])
                    sum += C[A[i - 1]-1];
            }
            Println(sum);
        }

        static List<long> ReadLines(long n)
        {
            var l = new List<long>();
            for (long i = 0; i < n; i++)
            {
                l.Add(ReadLong());
            }
            return l;
        }

        static void YESOrNO(bool e) => Println(e ? "YES" : "NO");

        static void YesOrNo(bool e) => Println(e ? "Yes" : "No");

        static IEnumerable<int> Range(int start, int stop)
        {
            if (start < 0 || stop < 0 || start > stop || (start <= 0 && stop <= 0))
                return new List<int>();

            return Enumerable.Range(start, stop - start);
        }

        static bool IsDigit(string str)
        {
            var i = 0;
            return int.TryParse(str, out i);
        }

        static int SumDigits(long num)
        {
            return num.ToString().Select(x => x.ToString()).Sum(int.Parse);
        }

        static int[] ToIntArray(string str)
        {
            return str.Select(x => x.ToString()).Select(int.Parse).ToArray();
        }

        static long Gcd(long a, long b) => b == 0 ? a : Gcd(b, a % b);
        static long Lcm(long a, long b) => a / Gcd(a, b) * b;

        static bool IsPrime(int x)
        {
            if (x <= 1 || (x != 2 && x % 2 == 0)) return false;
            if (x == 2) return true;

            for (int i = 3; i < x; i += 2)
                if (x % i == 0) return false;

            return true;
        }

        static string Read() => Console.ReadLine();
        static int ReadInt() => int.Parse(Read());
        static long ReadLong() => long.Parse(Read());

        static List<string> ReadSplit() => Read().Split().ToList();
        static List<int> ReadSplitInt() => Read().Split().Select(int.Parse).ToList();
        static List<long> ReadSplitLong() => Read().Split().Select(long.Parse).ToList();

        static void Print(object value) => Console.Write(value.ToString());
        static void Println(object value) => Console.WriteLine(value.ToString());
        static string Join<T>(IEnumerable<T> list) => string.Join("", list);
    }

    public static class MyExtensions
    {
        public static string Slice(this string str, int start = 0, int stop = 0)
        {
            if (start > str.Length || stop > str.Length || start < 0 || stop < 0)
                return "";

            if (stop == 0) stop = str.Length;
            return str.Substring(start, stop - start);
        }
    }
}