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

ans = 'A'

if abs(x-a)>abs(x-b):

  ans='B'

print(ans)



#print(*ans, sep='\n')

A, B, C = list(map(int, input().split()))

def check():

    if abs(B-A)<abs(C-A):

        return 'A'

    return 'B'

print((check()))
x, a, b = list(map(int, input().split()))
ans = "A"
if abs(x - a) > abs(x - b):
    ans = "B"
print(ans)
# print(*ans, sep='\n')

A, B, C = list(map(int, input().split()))


def check():
    if abs(B - A) < abs(C - A):
        return "A"
    return "B"


print((check()))

-x, a, b = list(map(int, input().split())) -ans = "A" -if abs(x - a) > abs(x - b): -    ans = "B" -print(ans) -# print(*ans, sep='\n') +A, B, C = list(map(int, input().split())) + + +def check(): +    if abs(B - A) < abs(C - A): +        return "A" +    return "B" + + +print((check()))