hw_list = []
for i in range(3):
    cur_list = [int(i) for i in input().split()]
    cur_list.insert(0, i)
    hw_list.append(cur_list)
    
sorted_hw_list = sorted(sorted_hw_list, key=lambda x:x[2])
sorted_hw_list = sorted(hw_list, key=lambda x:x[1], reverse=True)

for i in range(3):
    index = sorted_hw_list[i][0]
    print(chr(index + 65))