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 System.Text;

public class MainClass
{
	public const long Giri = 1000000007;

	
	public static void Main(string[] args)
	{
		int n = int.Parse(Console.ReadLine());
		string[] sa = Input();
		int[] a = new int [n];
		int[] b = new int [n];
		int[] c = new int [n-1];
		for(int i = 0; i < n; i++)
		{
			a[i] = int.Parse(sa[i]);
		}
		sa = Input();
		for(int i = 0; i < n; i++)
		{
			b[i] = int.Parse(sa[i]);
		}
		sa = Input();
		for(int i = 0; i < n-1; i++)
		{
			c[i] = int.Parse(sa[i]);
		}
		int m = 0;
		for(int i = 0; i < n; i++)
		{
			m += b[a[i]-1];
			//Console.WriteLine(b[a[i]-1]);
			if(i> 0)
			{
				if(a[i-1]+1 == a[i])
				{
					m += c[a[i-1]-1];
					//Console.WriteLine("add" + c[a[i-1]-1]);
				}
			}
		}
		Console.WriteLine(m);
	}
	
	public static long GCD(long a, long b)
	{
		if(b == 1)
			return a;
		long p = b / a;
		return GCD(a, b - a*p);
	}
	
	public static string[] Input()
	{
		return Console.ReadLine().Split(' ');
	}

	
	public static int Clamp(int val, int max, int min = 0)
	{
		return Math.Min(max, Math.Max(min, val));
	}

}