<reponame>ryosuke0825/atcoder_python
x, a, b = map(int, input().split())
if abs(x-a) > abs(x-b):
    print("B")
else:
    print("A")

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