import java.util.*;
 
public class Main {
 
	public static Scanner scan = new Scanner(System.in);
	public static void main(String[] args) {
      
 	String a = scan.next();
	      if(a.charAt(0) > 96 && a.charAt(0) < 123) 
	        System.out.println('a');
	      if(a.charAt(0) > 64 && a.charAt(0) < 91)
	        System.out.println('A');
    }
} import java.util.*; util.* java public class Main {
 
	public static Scanner scan = new Scanner(System.in);
	public static void main(String[] args) {
      
 	String a = scan.next();
	      if(a.charAt(0) > 96 && a.charAt(0) < 123) 
	        System.out.println('a');
	      if(a.charAt(0) > 64 && a.charAt(0) < 91)
	        System.out.println('A');
    }
} Main public static Scanner scan = new Scanner(System.in); scan new Scanner(System.in) public static void main(String[] args) {
      
 	String a = scan.next();
	      if(a.charAt(0) > 96 && a.charAt(0) < 123) 
	        System.out.println('a');
	      if(a.charAt(0) > 64 && a.charAt(0) < 91)
	        System.out.println('A');
    } main {
      
 	String a = scan.next();
	      if(a.charAt(0) > 96 && a.charAt(0) < 123) 
	        System.out.println('a');
	      if(a.charAt(0) > 64 && a.charAt(0) < 91)
	        System.out.println('A');
    } String a = scan.next(); a scan.next() scan.next scan if(a.charAt(0) > 96 && a.charAt(0) < 123) 
	        System.out.println('a'); a.charAt(0) > 96 && a.charAt(0) < 123 a.charAt(0) > 96 a.charAt(0) a.charAt a 0 96 a.charAt(0) < 123 a.charAt(0) a.charAt a 0 123 System.out.println('a') System.out.println System.out System System.out 'a' if(a.charAt(0) > 64 && a.charAt(0) < 91)
	        System.out.println('A'); a.charAt(0) > 64 && a.charAt(0) < 91 a.charAt(0) > 64 a.charAt(0) a.charAt a 0 64 a.charAt(0) < 91 a.charAt(0) a.charAt a 0 91 System.out.println('A') System.out.println System.out System System.out 'A' String[] args args public class Main {
 
	public static Scanner scan = new Scanner(System.in);
	public static void main(String[] args) {
      
 	String a = scan.next();
	      if(a.charAt(0) > 96 && a.charAt(0) < 123) 
	        System.out.println('a');
	      if(a.charAt(0) > 64 && a.charAt(0) < 91)
	        System.out.println('A');
    }
} public class Main {
 
	public static Scanner scan = new Scanner(System.in);
	public static void main(String[] args) {
      
 	String a = scan.next();
	      if(a.charAt(0) > 96 && a.charAt(0) < 123) 
	        System.out.println('a');
	      if(a.charAt(0) > 64 && a.charAt(0) < 91)
	        System.out.println('A');
    }
} Main
import java.util.*;
 
public class Main {
 
	public static Scanner scan = new Scanner(System.in);
	public static void main(String[] args) {
      
 	String a = scan.next();
	      if(a.charAt(0) > 96 && a.charAt(0) < 123) 
	        System.out.println('a');
	      if(a.charAt(0) > 64 && a.charAt(0) < 91)
	        System.out.println('A');
    }
}