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: Accepted)

use std::cmp::Ordering;
use std::str::FromStr;
use std::io;

fn main() {

	let mut line = String::new();
	io::stdin().read_line(&mut line);
	let split : Vec<&str> = line.split(' ').collect(); 

	let x = i32::from_str(split[0].trim()).unwrap();
	let a = i32::from_str(split[1].trim()).unwrap();
	let b = i32::from_str(split[2].trim()).unwrap();

	let xa = (a - x).abs();
	let xb = (b - x).abs();

	match xa.cmp(&xb) {
        Ordering::Less    => println!("A"),
        Ordering::Greater => println!("B"),
        Ordering::Equal => println!("Invalid"),
    }
}