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 Java8 (OpenJDK 1.8.0) (judge verdict: Accepted)

import java.io.IOException;
import java.io.InputStream;
import java.io.PrintWriter;
import java.util.*;

public class Main {
    public static void main(String[] args) {
        PrintWriter out = new PrintWriter(System.out);
        InputStreamScanner in = new InputStreamScanner(System.in);
        new Main().solve(in, out);
        out.flush();
    }

    private void solve(InputStreamScanner in, PrintWriter out) {
        int x = in.nextInt();
        int a = in.nextInt();
        int b = in.nextInt();

        out.println(Math.abs(x - a) > Math.abs(x -b) ? "B" : "A");
    }

    static class InputStreamScanner {

        private InputStream in;

        private byte[] buf = new byte[1024];
        private int len = 0;
        private int off = 0;

        InputStreamScanner(InputStream in)	{
            this.in = in;
        }

        String next() {
            StringBuilder sb = new StringBuilder();
            for (int b = skip(); !isSpace(b);){
                sb.appendCodePoint(b);
                b = read();
            }
            return sb.toString();
        }

        int nextInt() {
            return Integer.parseInt(next());
        }

        long nextLong() {
            return Long.parseLong(next());
        }

        double nextDouble() {
            return Double.parseDouble(next());
        }

        char nextChar() {
            return (char)skip();
        }

        int skip() {
            for (int b; (b = read()) != -1;) {
                if (!isSpace(b)) {
                    return b;
                }
            }
            return -1;
        }

        private boolean isSpace(int c) {
            return c < 33 || c > 126;
        }

        private int read() {
            if (len == -1) {
                throw new InputMismatchException("End of Input");
            }
            if (off >= len){
                off = 0;
                try {
                    len = in.read(buf);
                } catch (IOException e) {
                    throw new InputMismatchException(e.getMessage());
                }
                if (len <= 0) {
                    return -1;
                }
            }
            return buf[off++];
        }
    }
}