HA_dict = dict()

H, W = map(int, input().split())
HA_dict["A"] = (H, W)

H, W = map(int, input().split())
HA_dict["B"] = (H, W)
    
H, W = map(int, input().split())
HA_dict["C"] = (H, W)

HA_dict = sorted(HA_dict.items(), key=lambda x:x[1][1])
HA_dict = sorted(HA_dict, reverse=True, key=lambda x:x[1][0])

for i in range(3):
    print(HA_dict[i][0])