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 C# (Mono 4.6.2.0) (judge verdict: Accepted)

using System;
using System.Collections;
using System.Collections.Generic;
using System.Linq;
using System.Text;
using System.Threading.Tasks;
using System.Diagnostics;

namespace ConsoleApplication
{
    class Program
    {
        static void Main()
        {
            new Solution().answer();
        }
    }

    class Solution
    {
        string N, M, T;
        int x, a, b,d1,d2;
        public Solution()
        {
            N = Console.ReadLine();
            //M = Console.ReadLine();
            //int j = Convert.ToInt32(N);
            string[] M_split = new string[3];
            //string[] M_split_full = new string[j * 3];

            M_split = N.Split(' ');
            x=Convert.ToInt32(M_split[0]);
            a=Convert.ToInt32(M_split[1]);
            b=Convert.ToInt32(M_split[2]);

            d1=Math.Abs(a-x);
            d2=Math.Abs(b-x);

            if (d1 > d2) { T = "B"; } else { T = "A"; }

            //int a;
            //for (a = 0; a < j; a++)
            //{
            //    M_split_full[a] = M_split[a];
            //    M_split_full[j + a] = (Convert.ToInt32(M_split[a]) - 1).ToString();
            //    M_split_full[(2 * j) + a] = (Convert.ToInt32(M_split[a]) + 1).ToString();
            //}

            //var count =(from item in M_split_full
            //            group item by item into g
            //            select g.Count()).ToList();

            //var ans = (from item in count
            //           group item by item into g
            //           select g.Max()).ToList();

            //ans.Sort();
            //T = ans[ans.Count() - 1].ToString();                          
        }

        public void answer()
        {
            Console.WriteLine(T);
        }
    }
}