v= map(chr, range(65, 91))
i=0
j=0
c=[]
while i < 8:
x,y= raw_input().split(" ")
if x<y:
c+=[v[j+1]]
j+=2
else:
c+=[v[j]]
j+=2
i+=1
i=0
j=0
while i < 4:
x,y= raw_input().split(" ")
if x<y:
v+=[c[j+1]]
j+=2
else:
v+=[c[j]]
j+=2
i+=1
for k in v:
print k
dj0gbWFwKGNociwgcmFuZ2UoNjUsIDkxKSkKCmk9MApqPTAKYz1bXQp3aGlsZSBpIDwgODoKCXgseT0gcmF3X2lucHV0KCkuc3BsaXQoIiAiKQoJaWYgeDx5OgkJCgkJYys9W3ZbaisxXV0KCQlqKz0yCgllbHNlOgoJCWMrPVt2W2pdXQoJCWorPTIJCQoJaSs9MQoKaT0wCmo9MAoKd2hpbGUgaSA8IDQ6Cgl4LHk9IHJhd19pbnB1dCgpLnNwbGl0KCIgIikKCWlmIHg8eToJCQoJCXYrPVtjW2orMV1dCgkJais9MgoJZWxzZToKCQl2Kz1bY1tqXV0KCQlqKz0yCQkKCWkrPTEKCgpmb3IgayBpbiB2OgoJcHJpbnQgawo=