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 PHP7 (7.0.15) (judge verdict: Accepted)

<?php

class In {

	private $buf = [];
	private $count = 0;
	private $pointer = 0;

	public function nextLine() {
		$ret = '';
		if($this->hasNext()){
			while($this->hasNext()){
				$ret .= $this->next();
			}
		}else{
			$ret = trim(fgets(STDIN));
		}

		return $ret;
	}

	public function next() {
		if(!$this->hasNext()) {
			$str = trim(fgets(STDIN));
			$this->buf = explode(' ',$str);
			$this->count = count($this->buf);
			$this->pointer = 0;
		}

		return $this->buf[$this->pointer++];
	}

	public function hasNext() {
		return $this->pointer < $this->count;
	}

	public function nextInt() {
		return (int)$this->next();
	}

	public function nextDouble() {
		return (double)$this->next();
	}
}

class Out {
	public function println($str = '') {
		echo $str . PHP_EOL;
	}
}

$in = new In();
$out = new Out();

$x = $in->nextInt();
$a = $in->nextInt();
$b = $in->nextInt();

if (abs($x-$a) < abs($x-$b)) {
	$out->println('A');
} else {
	$out->println('B');
}

?>