/*
If you want to aim high, aim high
Don't let that studying and grades consume you
Just live life young
******************************
What do you think? What do you think?
1st on Billboard, what do you think of it
Next is a Grammy, what do you think of it
However you think, I’m sorry, but shit, I have no fcking interest
*******************************
I'm standing on top of my Monopoly board
That means I'm on top of my game and it don't stop
til my hip don't hop anymore
https://www.a2oj.com/Ladder16.html
*******************************
300iq as writer = Sad!
*/
import java.util.*;
import java.io.*;
import java.math.*;

   public class Main
   {
      public static void main(String hi[]) throws Exception
      {
         BufferedReader infile = new BufferedReader(new InputStreamReader(System.in));
         StringTokenizer st = new StringTokenizer(infile.readLine());
         char val = st.nextToken().charAt(0);
         if(val >= 'A' && val <= 'Z')
            System.out.println('A');
         else
            System.out.println('a');
      }
   } import java.util.*; util.* java import java.io.*; io.* java import java.math.*; math.* java public class Main
   {
      public static void main(String hi[]) throws Exception
      {
         BufferedReader infile = new BufferedReader(new InputStreamReader(System.in));
         StringTokenizer st = new StringTokenizer(infile.readLine());
         char val = st.nextToken().charAt(0);
         if(val >= 'A' && val <= 'Z')
            System.out.println('A');
         else
            System.out.println('a');
      }
   } Main public static void main(String hi[]) throws Exception
      {
         BufferedReader infile = new BufferedReader(new InputStreamReader(System.in));
         StringTokenizer st = new StringTokenizer(infile.readLine());
         char val = st.nextToken().charAt(0);
         if(val >= 'A' && val <= 'Z')
            System.out.println('A');
         else
            System.out.println('a');
      } main {
         BufferedReader infile = new BufferedReader(new InputStreamReader(System.in));
         StringTokenizer st = new StringTokenizer(infile.readLine());
         char val = st.nextToken().charAt(0);
         if(val >= 'A' && val <= 'Z')
            System.out.println('A');
         else
            System.out.println('a');
      } BufferedReader infile = new BufferedReader(new InputStreamReader(System.in)); infile new BufferedReader(new InputStreamReader(System.in)) StringTokenizer st = new StringTokenizer(infile.readLine()); st new StringTokenizer(infile.readLine()) char val = st.nextToken().charAt(0); val st.nextToken().charAt(0) st.nextToken().charAt st.nextToken() st.nextToken st 0 if(val >= 'A' && val <= 'Z')
            System.out.println('A');
         else
            System.out.println('a'); val >= 'A' && val <= 'Z' val >= 'A' val 'A' val <= 'Z' val 'Z' System.out.println('A') System.out.println System.out System System.out 'A' System.out.println('a') System.out.println System.out System System.out 'a' String hi[] hi public class Main
   {
      public static void main(String hi[]) throws Exception
      {
         BufferedReader infile = new BufferedReader(new InputStreamReader(System.in));
         StringTokenizer st = new StringTokenizer(infile.readLine());
         char val = st.nextToken().charAt(0);
         if(val >= 'A' && val <= 'Z')
            System.out.println('A');
         else
            System.out.println('a');
      }
   } public class Main
   {
      public static void main(String hi[]) throws Exception
      {
         BufferedReader infile = new BufferedReader(new InputStreamReader(System.in));
         StringTokenizer st = new StringTokenizer(infile.readLine());
         char val = st.nextToken().charAt(0);
         if(val >= 'A' && val <= 'Z')
            System.out.println('A');
         else
            System.out.println('a');
      }
   } Main
/*
If you want to aim high, aim high
Don't let that studying and grades consume you
Just live life young
******************************
What do you think? What do you think?
1st on Billboard, what do you think of it
Next is a Grammy, what do you think of it
However you think, I’m sorry, but shit, I have no fcking interest
*******************************
I'm standing on top of my Monopoly board
That means I'm on top of my game and it don't stop
til my hip don't hop anymore
https://www.a2oj.com/Ladder16.html
*******************************
300iq as writer = Sad!
*/
import java.util.*;
import java.io.*;
import java.math.*;

   public class Main
   {
      public static void main(String hi[]) throws Exception
      {
         BufferedReader infile = new BufferedReader(new InputStreamReader(System.in));
         StringTokenizer st = new StringTokenizer(infile.readLine());
         char val = st.nextToken().charAt(0);
         if(val >= 'A' && val <= 'Z')
            System.out.println('A');
         else
            System.out.println('a');
      }
   }