alpha = eval(input())



if alpha.isupper():

  print('A')

else:

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

print(('A' if a.isupper() else 'a'))
alpha = eval(input())
if alpha.isupper():
    print("A")
else:
    print("a")

a = eval(input())
print(("A" if a.isupper() else "a"))

-alpha = eval(input()) -if alpha.isupper(): -    print("A") -else: -    print("a") +a = eval(input()) +print(("A" if a.isupper() else "a"))