Problem:
Score : 100 points

Problem Statement

An uppercase or lowercase English letter \alpha will be given as input.
If \alpha is uppercase, print A; if it is lowercase, print a.

Constraints

\alpha is an uppercase (A - Z) or lowercase (a - z) English letter.

Input

Input is given from Standard Input in the following format:

α

Output

If \alpha is uppercase, print A; if it is lowercase, print a.

Sample Input 1

B

Sample Output 1

A

B is uppercase, so we should print A.

Sample Input 2

a

Sample Output 2

a

a is lowercase, so we should print a.

Solution in Ruby (2.7.1) (judge verdict: Wrong Answer)

n = gets.to_i

# 26進数

chars = ('a'..'z').to_a

result = ''

while n > 0
  n -= 1
  result << chars[n % 26]
  n /= 26
end

puts result.reverse