a = int(input())
b = int(input())
c = int(input())

H = [a,b,c]
if max(H)==a:
    mx='A'
elif max(H)==b:
    mx='B'
else:
    mx='C'

if min(H)==a:
    mn='A'
elif min(H)==b:
    mn='B'
else:
    mn='C'

print(mx)
if 'A'!=mx and 'A'!=mn:
    print('A')
elif 'B'!=mx and 'B'!=mn:
    print('B')
else:
    print('C')
print(mn)