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 Go (1.6) (judge verdict: Accepted)

package main

import (
	"bufio"
	"fmt"
	"os"
	"strconv"
	"strings"
)

func toI(ss []string) []int {
	ret := make([]int, 0, len(ss))
	for _, s := range ss {
		n, _ := strconv.Atoi(strings.TrimSpace(s))
		ret = append(ret, n)
	}
	return ret
}

func main() {
	var n int
	fmt.Scan(&n)

	reader := bufio.NewReader(os.Stdin)

	A, _ := reader.ReadString('\n')
	B, _ := reader.ReadString('\n')
	C, _ := reader.ReadString('\n')

	a := toI(strings.Split(A, " "))
	b := toI(strings.Split(B, " "))
	c := toI(strings.Split(C, " "))

	sum := 0
	for i := 0; i < n; i++ {
		sum += b[i]
		if i > 0 && a[i-1]+1 == a[i] {
			sum += c[a[i-1]-1]
		}
	}
	fmt.Println(sum)
}