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|.
import itertools
s = input()
cnt = ord('a')
for k, _ in itertools.groupby(sorted(s)):
  if not cnt == ord(k):
    break
  cnt += 1
print([chr(cnt), 'None'][cnt>ord('z')])
x,a,b=map(int,input().split())
if abs(x-a) < abs(x-b):
  print('A')
else:
  print('B')