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.BufferedReader;
import java.io.IOException;
import java.io.InputStreamReader;

public class Main {

	public static void main(String[] args) throws IOException, Exception{
		BufferedReader st = new BufferedReader(new InputStreamReader(System.in));
		int n = getInt(st);
		int[] a = getIntArry(st);
		int[] b = getIntArry(st);
		int[] c = getIntArry(st);
		int ans = 0;
		int preNo = 0;
		for (int i = 0; i < n; i++) {
			ans = ans + b[a[i]-1];
			if (preNo == 0) {
				preNo = a[i];
			} else if(preNo == a[i]-1) {
				ans = ans + c[a[i]-2];
			}
			preNo = a[i];
			/*
			if (i == n-1 && a[i]-2 >= 0) {
				ans = ans + c[a[i]-2];
				anser(c[a[i]-2]);
			}
			*/
		}
		anser(ans);
	}

	private static int getInt(BufferedReader st) throws Exception, IOException {
		int num = Integer.parseInt(st.readLine());
		return num;
	}

	private static int[] getIntArry(BufferedReader st) throws Exception, IOException {
		String line = st.readLine();
		String[] strData = line.split(" ");
		int[] intData = new int[strData.length];
		for (int i = 0; i < strData.length; i++) {
			intData[i] = Integer.parseInt(strData[i]);
		}
		return intData;
	}

	private static void anser(int num) {
		System.out.println(num);
	}


}