# your code goes here
class Human:
	def __init__(self, name, h, w):
		self.name = name
		self.h = h
		self.w = w

list1 = []
for i in range(3):
	h, w = map(int, input().split())
	name = chr(ord('A') + i)
	list1.append(Human(name, h, w))
list1.sort(key = lambda a: a.w)
list1.sort(key = lambda a: a.h, reverse = True)
for i in range(3):
	print(list1[i].name)