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|.
# -*- coding: utf-8 -*-


def main():
    """Function."""
    x, a, b = map(int, input().split())
    if abs(a - x) < abs(b - x):
        print("A")
    else:
        print("b")


if __name__ == "__main__":
    main()

# -*- coding: utf-8 -*-


def main():
    """Function."""
    x, a, b = map(int, input().split())
    if abs(a - x) < abs(b - x):
        print("A")
    else:
        print("B")


if __name__ == "__main__":
    main()
