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: Runtime Error)

using System;
using System.Linq;
using System.Collections.Generic;
class Program
{
    static void Main(string[] args)
    {
        int N = int.Parse(Console.ReadLine());
        int[] A = Console.ReadLine().Split(' ').Select(int.Parse).ToArray();
        Array.Sort(A);
      
        int x = 0;
        int y = 0;
        int i = N - 1;
        for(;i > 0;i--)
        {
          if(A[i] == A[i - 1])
          {
            x = A[i];
            i -= 2;
            break;
          }
        }
        for(; i > 0;i--)
        {
          if(A[i] == A[i - 1])
          {
            y = A[i];
            break;
          }
        }
      
      Console.WriteLine((long)x*y);
    }
}