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: Wrong Answer)

use std::collections::HashMap;

fn main() {
    let mut s = String::new();
    std::io::stdin().read_line(&mut s).unwrap();
    let mut s = String::new();
    std::io::stdin().read_line(&mut s).unwrap();
    let a: Vec<usize> = s.trim().split_whitespace().map(|x| x.parse().unwrap()).collect();

    let mut h: HashMap<usize, usize> = HashMap::new();
    for i in &a {
        let x = match h.get(i) {Some(x) => *x, None => 0};
        h.insert(*i, x+1);
    }
    let mut x = 0;
    let mut y = 0;
    for (i, j) in &h {
        let mut b = false;
        if *i > x && *j >= 2 {x = *i; b = true;}
        if *i > y && ((b && *j >= 4) || (!b && *j >= 2)) {y = *i;}
    }

    println!("{}", x * y);
}