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 Java8 (OpenJDK 1.8.0) (judge verdict: Accepted)

import java.io.*;
import java.util.*;

public class Main {
	public static void main(String[] args) {
		InputStreamReader isr;
		BufferedReader br;
		try {
	   		br = createBufferedReader();
	        String line = br.readLine();
	    	final int n = Integer.parseInt(line);
	        if (n < 2 || n > 20) {
	        	throw new IllegalArgumentException();
	        }
	        int[] a = new int[n];
	        int[] b = new int[n];
	        int[] c = new int[n - 1];
	        line = br.readLine();
	        StringTokenizer st = new StringTokenizer(line, " ");
	        for (int i = 0; i < n; i++) {
	        	a[i] = Integer.parseInt(st.nextToken());
	        }
	        line = br.readLine();
	        st = new StringTokenizer(line, " ");
	        for (int i = 0; i < n; i++) {
	        	b[i] = Integer.parseInt(st.nextToken());
	        }
	        line = br.readLine();
	        st = new StringTokenizer(line, " ");
	        for (int i = 0; i < n - 1; i++) {
	        	c[i] = Integer.parseInt(st.nextToken());
	        }
	        int result = 0;
	        for (int i = 0; i < n; i++) {
	        	result += b[a[i] - 1];
	        	if (i > 0 && a[i] - a[i - 1] == 1) {
	        		result += c[a[i] - 2];
	        	}
	        }
	        System.out.println(result);
		} catch (IOException ioe) {
			ioe.printStackTrace();
		} catch (IllegalArgumentException iae) {
			iae.printStackTrace();
			System.err.println("入力が正しくありません。");
		}
	}

	// 以下問題問わずに共通部分
	// 標準入力の BufferedReader を返す.
	private static BufferedReader createBufferedReader() {
		InputStreamReader isr =new InputStreamReader(System.in);
	   	return new BufferedReader(isr);
	}
}