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
v=[]
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
i=0
j=0
c=[]
while i < 2:
x,y= raw_input().split(" ")
if x<y:
c+=[v[j+1]]
j+=2
else:
c+=[v[j]]
j+=2
i+=1
if x<y:
print c[1]
else
print c[0]
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