s = eval(input())



if s == s.upper():

    print('A')

else:

    print('a')
s = eval(input())

if s.islower():

    print('a')

else:

    print('A')
s = eval(input())
if s == s.upper():
    print("A")
else:
    print("a")

s = eval(input())
if s.islower():
    print("a")
else:
    print("A")

-if s == s.upper(): +if s.islower(): +    print("a") +else: -else: -    print("a")