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::*;

fn main() {
    let mut x = read();
    let mut a = read();
    let mut b = read();

    let ax = zet(a - x);
    let bx = zet(b - x);

    let out = stdout();
    let mut out = BufWriter::new(out.lock());

    if ax > bx {
        out.write(b"B");
    } else {
        out.write(b"A");
    }
}

fn zet(mut x: i32) -> i32 {
    if x < 0 {
        x = -x;
    }
    x
}

//fn read_v() -> Vec<char> {
//    let s = stdin();
//    //    let mut s = BufReader::new(s.lock());
//    let b = s.bytes()
//        .map(|c| c.unwrap() as char)
//        .take_while(|c| !c.is_whitespace())
//        .collect();
//    b
//}

// fn read_t() -> (u32, u32) {
//     let mut s = String::new();
//     stdin().read_line(&mut s).expect("failed read_t");
//     let mut i = s.split_whitespace().map(|c| c.parse().ok().unwrap());
//     (i.next().unwrap(), i.next().unwrap())
// }

fn read() -> i32 {
    let s = stdin();
    //    let mut s = BufReader::new(s.lock());
    let b = s.bytes()
        .map(|c| c.unwrap() as char)
        .take_while(|c| !c.is_whitespace())
        .collect::<String>();
    b.parse().ok().expect("read() failed")
}