# define

tall_dic = {"A" : 0, "B": 0, "C": 0}

# input

for i in tall_dic:
    tall_dic[i] = int(input())

# sort
li = sorted(
    tall_dic.items(),
    key=lambda x: x[1],
    reverse=True)

# output

for name,value in li:
    print(name)