alpha = eval(input())



if alpha.isupper():

    print('A')

else:

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

if N.isupper():

    print('A')

else:

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

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

-alpha = eval(input()) -if alpha.isupper(): +N = eval(input()) +if N.isupper():