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|.
S = input()
ans = 'None'
for letter in "abcdefghijklmnopqrstuvwxyz":
    if letter not in S:
        ans = letter
        break
print(ans)
x, a, b = map(int, input().split())
ax = int((((a-x)**2)**0.5)//1)
bx = int((((b-x)**2)**0.5)//1)
print('A') if ax < bx else print('B')