import re

a=eval(input())

if re.sub(r'[A-Z]',"",a)=="":

  print('A')

else:

  print('a')

a=eval(input())

if a.isupper():

  print('A')

else:

  print('a')
import re

a = eval(input())
if re.sub(r"[A-Z]", "", a) == "":
    print("A")
else:
    print("a")

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

-import re - -if re.sub(r"[A-Z]", "", a) == "": +if a.isupper():