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::io;
use std::cmp;
use std::collections::BinaryHeap;

macro_rules! read {
    ($t:ty) => {
        {
            let mut buf = String::new();
            io::stdin().read_line(&mut buf);
            let mut sp = buf.trim().split(" ");
            sp.next().unwrap().parse::<$t>().unwrap()
        }
    };
    ( $( $t:ty ),* ) => {
        {
            let mut buf = String::new();
            io::stdin().read_line(&mut buf);
            let mut sp = buf.trim().split(" ");
            ($(
                {
                    sp.next().unwrap().parse::<$t>().unwrap()
                },
            )*)
        }
    };
}
macro_rules! read_vec {
    ($t:ty) => {
        {
            let mut buf = String::new();
            io::stdin().read_line(&mut buf);
            let mut sp = buf.trim().split(" ");
            let mut ret = vec![];
            for s in sp {
                ret.push(s.parse::<$t>().unwrap());
            }
            ret
        }
    }
}

fn main() {
    let (x, a, b) = read!(i32, i32, i32);
    let da = (x - a).abs();
    let db = (x - b).abs();
    if da < db {
        println!("A");
    } else {
        println!("B");
    }
}