
{-# LANGUAGE StandaloneDeriving #-}
{-# LANGUAGE BangPatterns #-}

module Main where

import Debug.Trace
--import qualified Data.Set.Strict as Set
--import qualified Data.Map.Strict as Map

main :: IO ()
main = do
  a <- getLine
  --a `traceShow`
  putStrLn . solve . head $ a

solve :: Char -> String
solve a = if a >= 'a' && a <= 'z' then "a" else "A"
