a = map(int, raw_input().split())
b = map(int, raw_input().split())
c = map(int, raw_input().split())
brothers = [a,b,c]
num = 0

while brothers[0][0] <= brothers[1][0] or brothers[1][0] <= brothers[2][0]:
    if brothers[0][0] <= brothers[1][0]:
        brothers = [brothers[1],brothers[0],brothers[2]]
    elif brothers[1][0] <= brothers[2][0]:
        brothers = [brothers[0],brothers[2],brothers[1]]

while num < 5:
    if brothers[0][0] == brothers[1][0]:
        if brothers[0][1] >= brothers[1][1]:
            brothers = [brothers[0],brothers[1],brothers[2]]
        else:
            brothers = [brothers[1],brothers[0],brothers[2]]
    elif brothers[1][0] == brothers[2][0]:
        if brothers[1][1] >= brothers[2][0]:
            brothers = [brothers[0],brothers[1],brothers[2]]
        else:
            brothers = [brothers[0],brothers[2],brothers[1]]
    num += 1
brothers[brothers.index(a)] = 'A'
brothers[brothers.index(b)] = 'B'
brothers[brothers.index(c)] = 'C'
for i in brothers:
    print(i)