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 Perl (v5.18.2) (judge verdict: Wrong Answer)

use strict;
use warnings;
use utf8;
 
use feature qw/say/;
 
my $n = <>;
my @a = split(/\s+/, <>);
 
my %cnt; $cnt{$_} = ($cnt{$_} // 0) + 1 for (@a);
my ($first, $second) = sort { $b <=> $a } grep { $cnt{$_} >= 2 } (keys %cnt);
 
say !defined $first   ? 0
  : $cnt{$first} >= 4 ? $first * $first
  :                     $first * ($second // 0);