ha,wa=[*map(int,input().split())]
hb,wb=[*map(int,input().split())]
hc,wc=[*map(int,input().split())]
T=[];t='ABC'
H=[ha,hb,hc];W=[wa,wb,wc]
for i in range(3):
    T.append((H[i],W[i],t[i]))
T=sorted(T,key=lambda x:(-x[0],x[1]))
[print(i[2]) for i in T]