# import sys; input = sys.stdin.buffer.readline
# sys.setrecursionlimit(10**7)
from collections import defaultdict
con = 10 ** 9 + 7; INF = float("inf")

def getlist():
	return list(map(int, input().split()))

#処理内容
def main():
	HA = int(input())
	HB = int(input())
	HC = int(input())
	L = [[HA, "A"], [HB, "B"], [HC, "C"]]
	L.sort()

	for i in range(3):
		print(L[-1 - i][1])


if __name__ == '__main__':
	main()