# your code goes here
def c(l,m):
    if l[1]>m[1]:
        return 1
    elif m[1]>l[1]:
        return 0
    elif l[2]<m[2]:
        return 1
    else:
        return 0
def s(li,n1,n2):
    t=li[n1]
    li[n1]=li[n2]
    li[n2]=t
    return li  
g=[["A"],["B"],["C"]]
for i in range(3):
    g[i]+=[int(i) for i in input().split()]
#print(g)
if c(g[0],g[1])==0:
    g=s(g,0,1)
if c(g[0],g[2])==0:
    g=s(g,0,2)
    g=s(g,1,2)
elif c(g[1],g[2])==0:
    g=s(g,1,2)
for i in range(3):
    print(g[i][0])