import java.io.*;

public class Main{
	public static void main(String[] args){
      try{
    	BufferedReader br = new BufferedReader(new InputStreamReader(System.in));
      String str = br.readLine();
      if(Character.isUpperCase(str.charAt( 0 ))){
      	System.out.println("A");
      }
      else{
        System.out.println("a");
      }
      }
      catch(IOException e){
      	System.out.println("a");
      }
    }
} import java.io.*; io.* java public class Main{
	public static void main(String[] args){
      try{
    	BufferedReader br = new BufferedReader(new InputStreamReader(System.in));
      String str = br.readLine();
      if(Character.isUpperCase(str.charAt( 0 ))){
      	System.out.println("A");
      }
      else{
        System.out.println("a");
      }
      }
      catch(IOException e){
      	System.out.println("a");
      }
    }
} Main public static void main(String[] args){
      try{
    	BufferedReader br = new BufferedReader(new InputStreamReader(System.in));
      String str = br.readLine();
      if(Character.isUpperCase(str.charAt( 0 ))){
      	System.out.println("A");
      }
      else{
        System.out.println("a");
      }
      }
      catch(IOException e){
      	System.out.println("a");
      }
    } main {
      try{
    	BufferedReader br = new BufferedReader(new InputStreamReader(System.in));
      String str = br.readLine();
      if(Character.isUpperCase(str.charAt( 0 ))){
      	System.out.println("A");
      }
      else{
        System.out.println("a");
      }
      }
      catch(IOException e){
      	System.out.println("a");
      }
    } try{
    	BufferedReader br = new BufferedReader(new InputStreamReader(System.in));
      String str = br.readLine();
      if(Character.isUpperCase(str.charAt( 0 ))){
      	System.out.println("A");
      }
      else{
        System.out.println("a");
      }
      }
      catch(IOException e){
      	System.out.println("a");
      } catch(IOException e){
      	System.out.println("a");
      } IOException e {
      	System.out.println("a");
      } System.out.println("a") System.out.println System.out System System.out "a" {
    	BufferedReader br = new BufferedReader(new InputStreamReader(System.in));
      String str = br.readLine();
      if(Character.isUpperCase(str.charAt( 0 ))){
      	System.out.println("A");
      }
      else{
        System.out.println("a");
      }
      } BufferedReader br = new BufferedReader(new InputStreamReader(System.in)); br new BufferedReader(new InputStreamReader(System.in)) String str = br.readLine(); str br.readLine() br.readLine br if(Character.isUpperCase(str.charAt( 0 ))){
      	System.out.println("A");
      }
      else{
        System.out.println("a");
      } Character.isUpperCase(str.charAt( 0 )) Character.isUpperCase Character str.charAt( 0 ) str.charAt str 0 {
      	System.out.println("A");
      } System.out.println("A") System.out.println System.out System System.out "A" {
        System.out.println("a");
      } System.out.println("a") System.out.println System.out System System.out "a" String[] args args public class Main{
	public static void main(String[] args){
      try{
    	BufferedReader br = new BufferedReader(new InputStreamReader(System.in));
      String str = br.readLine();
      if(Character.isUpperCase(str.charAt( 0 ))){
      	System.out.println("A");
      }
      else{
        System.out.println("a");
      }
      }
      catch(IOException e){
      	System.out.println("a");
      }
    }
} public class Main{
	public static void main(String[] args){
      try{
    	BufferedReader br = new BufferedReader(new InputStreamReader(System.in));
      String str = br.readLine();
      if(Character.isUpperCase(str.charAt( 0 ))){
      	System.out.println("A");
      }
      else{
        System.out.println("a");
      }
      }
      catch(IOException e){
      	System.out.println("a");
      }
    }
} Main
import java.io.*;

public class Main{
	public static void main(String[] args){
      try{
    	BufferedReader br = new BufferedReader(new InputStreamReader(System.in));
      String str = br.readLine();
      if(Character.isUpperCase(str.charAt( 0 ))){
      	System.out.println("A");
      }
      else{
        System.out.println("a");
      }
      }
      catch(IOException e){
      	System.out.println("a");
      }
    }
}
