import java.util.Arrays;
import java.util.Scanner;
 
public class Main {
	public static void main (String[] args) {
      Scanner sc = new Scanner(System.in); 
   
        // Character input 
       char c = sc.next().charAt(0); 
       if(c>='A' && c<='Z'){
         System.out.println("A");
       }else{
       	System.out.println("a");
       }
    }
} import java.util.Arrays; Arrays java.util import java.util.Scanner; Scanner java.util public class Main {
	public static void main (String[] args) {
      Scanner sc = new Scanner(System.in); 
   
        // Character input 
       char c = sc.next().charAt(0); 
       if(c>='A' && c<='Z'){
         System.out.println("A");
       }else{
       	System.out.println("a");
       }
    }
} Main public static void main (String[] args) {
      Scanner sc = new Scanner(System.in); 
   
        // Character input 
       char c = sc.next().charAt(0); 
       if(c>='A' && c<='Z'){
         System.out.println("A");
       }else{
       	System.out.println("a");
       }
    } main {
      Scanner sc = new Scanner(System.in); 
   
        // Character input 
       char c = sc.next().charAt(0); 
       if(c>='A' && c<='Z'){
         System.out.println("A");
       }else{
       	System.out.println("a");
       }
    } Scanner sc = new Scanner(System.in); sc new Scanner(System.in) char c = sc.next().charAt(0); c sc.next().charAt(0) sc.next().charAt sc.next() sc.next sc 0 if(c>='A' && c<='Z'){
         System.out.println("A");
       }else{
       	System.out.println("a");
       } c>='A' && c<='Z' c>='A' c 'A' c<='Z' c 'Z' {
         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) {
      Scanner sc = new Scanner(System.in); 
   
        // Character input 
       char c = sc.next().charAt(0); 
       if(c>='A' && c<='Z'){
         System.out.println("A");
       }else{
       	System.out.println("a");
       }
    }
} public class Main {
	public static void main (String[] args) {
      Scanner sc = new Scanner(System.in); 
   
        // Character input 
       char c = sc.next().charAt(0); 
       if(c>='A' && c<='Z'){
         System.out.println("A");
       }else{
       	System.out.println("a");
       }
    }
} Main
import java.util.Arrays;
import java.util.Scanner;
 
public class Main {
	public static void main (String[] args) {
      Scanner sc = new Scanner(System.in); 
   
        // Character input 
       char c = sc.next().charAt(0); 
       if(c>='A' && c<='Z'){
         System.out.println("A");
       }else{
       	System.out.println("a");
       }
    }
}