Problem:
Score : 100 points

Problem Statement

Snuke lives at position x on a number line.
On this line, there are two stores A and B, respectively at position a and b, that offer food for delivery.

Snuke decided to get food delivery from the closer of stores A and B.
Find out which store is closer to Snuke's residence.

Here, the distance between two points s and t on a number line is represented by |s-t|.

Constraints

1 \leq x \leq 1000

1 \leq a \leq 1000

1 \leq b \leq 1000

x, a and b are pairwise distinct.

The distances between Snuke's residence and stores A and B are different.

Input

Input is given from Standard Input in the following format:

x a b

Output

If store A is closer, print A; if store B is closer, print B.

Sample Input 1

5 2 7

Sample Output 1

B

The distances between Snuke's residence and stores A and B are 3 and 2, respectively.
Since store B is closer, print B.

Sample Input 2

1 999 1000

Sample Output 2

A

Solution in Rust (1.15.1) (judge verdict: Runtime Error)

use std::str::FromStr;
use std::fmt::Debug;
use std::cmp;

#[allow(dead_code)]
fn read_as_vec<T>() -> Vec<T>
where T: FromStr, <T as FromStr>::Err : Debug{
    let mut s = String::new();
    std::io::stdin().read_line(&mut s).unwrap();
    s.trim().split_whitespace().map(|c| T::from_str(c).unwrap()).collect()

}

#[allow(dead_code)]
fn read_as_string() -> String{
    let mut s = String::new();
    std::io::stdin().read_line(&mut s).unwrap();
    s.trim().to_string()
}


fn is_X(s: &Vec<Vec<(char, u64)>>, i: usize) -> bool{
    return s[0][i].0 == s[1][i].0;
}

fn is_Y(s: &Vec<Vec<(char, u64)>>, i: usize) -> bool{
    return !is_X(s, i);
}

fn main(){
    let n: usize = read_as_vec()[0];

    let mut s: Vec<Vec<(char, u64)>> = Vec::new();

    s.push(read_as_string().chars().zip(vec![0;n].into_iter()).collect::<Vec<(char, u64)>>());
    s.push(read_as_string().chars().zip(vec![0;n].into_iter()).collect::<Vec<(char, u64)>>());

    //init
    let mut i = 0;
    let mut ans: u64;
    let mut is_prev_x: bool;

    if is_X(&s, i){
        ans = 3;
        i += 1;
        is_prev_x = true;
    }else{
        ans = 6;
        i += 2;
        is_prev_x = false;
    }

    while i < n{
        if is_X(&s, i){
            if is_prev_x{
                ans *= 2;
            }else{
                ans *= 1;
            }
            i += 1;
            is_prev_x = true;
        }else{
            if is_prev_x{
                ans *= 2;
            }else{
                ans *= 3;
            }
            i += 2;
            is_prev_x = false;
        }
        ans %= 1_000_000_007;
    }

    println!("{:?}", ans);
}