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 Rust (1.42.0) (judge verdict: Accepted)

fn main() {
    let n: usize = read_line_as_value();
    let a_in: Vec<usize> = read_line_as_vector();
    let b_in: Vec<usize> = read_line_as_vector();
    let c_in: Vec<usize> = read_line_as_vector();

    let mut prev = 0;
    let mut ans = 0;
    for i in 0..n {
        if i == 0 {
            ans += b_in[a_in[i]-1];
        } else {
            ans += b_in[a_in[i]-1];
            if prev == a_in[i] - 1 {
                ans += c_in[prev-1];
            }
        }
        prev = a_in[i];
    }
    println!("{}", ans);
}

fn read_line_as_value<T: std::str::FromStr>() -> T {
    let mut input = String::new();
    let res = std::io::stdin().read_line(&mut input);
    if let Err(error) = res {
        panic!("io error at stdin.read_line: {}", error);
    };
    match input.trim().parse() {
        Ok(val) => val,
        _ => panic!("error while parsing input: {}", input)
    }
}

fn read_line_as_vector<T: std::str::FromStr>() -> Vec<T> {
    let mut input = String::new();
    let res = std::io::stdin().read_line(&mut input);
    if let Err(error) = res {
        panic!("io error at stdin.read_line: {}", error);
    };
    match input.trim().split_whitespace().map(|x| x.parse()).collect::<Result<Vec<T>, _>>() {
        Ok(vec) => vec,
        _ => panic!("error while parsing input: {}", input)
    }
}