def print_ans(x,a,b):

    """Print min(abs(x-a),abs(x-b))



    Parameters

    --------------



    Examples

    ------------

    >>> print_ans(3,0,1)

    B

    >>> print_ans(3,2,5)

    A

    >>> print_ans(2,5,9)

    A

    """

    #print(min(abs(x-a),abs(x-b)))

    if min(abs(x-a),abs(x-b)) == abs(x-b):

      print("B")

    else:

      print("A")









if __name__ == '__main__':

    x,a,b = list(map(int,input().split()))

    print_ans(x,a,b)

#!/usr/bin/env python3

import sys



n,a,b = list(map(int,input().split()))

#print(min(abs(n-a),abs(n-b)))

print(("A" if abs(n-a) < abs(n-b) else "B" ))
def print_ans(x, a, b):
    """Print min(abs(x-a),abs(x-b))
    Parameters
    --------------
    Examples
    ------------
    >>> print_ans(3,0,1)
    B
    >>> print_ans(3,2,5)
    A
    >>> print_ans(2,5,9)
    A
    """
    # print(min(abs(x-a),abs(x-b)))
    if min(abs(x - a), abs(x - b)) == abs(x - b):
        print("B")
    else:
        print("A")


if __name__ == "__main__":
    x, a, b = list(map(int, input().split()))
    print_ans(x, a, b)

#!/usr/bin/env python3
import sys

n, a, b = list(map(int, input().split()))
# print(min(abs(n-a),abs(n-b)))
print(("A" if abs(n - a) < abs(n - b) else "B"))

-def print_ans(x, a, b): -    """Print min(abs(x-a),abs(x-b)) -    Parameters -    Examples -    >>> print_ans(3,0,1) -    B -    >>> print_ans(3,2,5) -    A -    >>> print_ans(2,5,9) -    A -    """ -    # print(min(abs(x-a),abs(x-b))) -    if min(abs(x - a), abs(x - b)) == abs(x - b): -        print("B") -    else: -        print("A") +#!/usr/bin/env python3 +import sys - -if __name__ == "__main__": -    x, a, b = list(map(int, input().split())) -    print_ans(x, a, b) +n, a, b = list(map(int, input().split())) +# print(min(abs(n-a),abs(n-b))) +print(("A" if abs(n - a) < abs(n - b) else "B"))