import java.util.*;
import java.util.Arrays;
public class Main{
    public static void main(String[] args){
      Scanner sc = new Scanner(System.in);
      String x = sc.next();
      char []a = x.toCharArray();
      if(Character.isUpperCase(a[0])){
        System.out.println("A");
      }
      else{
        System.out.println("a");
    
      }
      
      
      
      

     
    }
   
    
       
    
} import java.util.*; util.* java import java.util.Arrays; Arrays java.util public class Main{
    public static void main(String[] args){
      Scanner sc = new Scanner(System.in);
      String x = sc.next();
      char []a = x.toCharArray();
      if(Character.isUpperCase(a[0])){
        System.out.println("A");
      }
      else{
        System.out.println("a");
    
      }
      
      
      
      

     
    }
   
    
       
    
} Main public static void main(String[] args){
      Scanner sc = new Scanner(System.in);
      String x = sc.next();
      char []a = x.toCharArray();
      if(Character.isUpperCase(a[0])){
        System.out.println("A");
      }
      else{
        System.out.println("a");
    
      }
      
      
      
      

     
    } main {
      Scanner sc = new Scanner(System.in);
      String x = sc.next();
      char []a = x.toCharArray();
      if(Character.isUpperCase(a[0])){
        System.out.println("A");
      }
      else{
        System.out.println("a");
    
      }
      
      
      
      

     
    } Scanner sc = new Scanner(System.in); sc new Scanner(System.in) String x = sc.next(); x sc.next() sc.next sc char []a = x.toCharArray(); a x.toCharArray() x.toCharArray x if(Character.isUpperCase(a[0])){
        System.out.println("A");
      }
      else{
        System.out.println("a");
    
      } Character.isUpperCase(a[0]) Character.isUpperCase Character a[0] a 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){
      Scanner sc = new Scanner(System.in);
      String x = sc.next();
      char []a = x.toCharArray();
      if(Character.isUpperCase(a[0])){
        System.out.println("A");
      }
      else{
        System.out.println("a");
    
      }
      
      
      
      

     
    }
   
    
       
    
} public class Main{
    public static void main(String[] args){
      Scanner sc = new Scanner(System.in);
      String x = sc.next();
      char []a = x.toCharArray();
      if(Character.isUpperCase(a[0])){
        System.out.println("A");
      }
      else{
        System.out.println("a");
    
      }
      
      
      
      

     
    }
   
    
       
    
} Main
import java.util.*;
import java.util.Arrays;
public class Main{
    public static void main(String[] args){
      Scanner sc = new Scanner(System.in);
      String x = sc.next();
      char []a = x.toCharArray();
      if(Character.isUpperCase(a[0])){
        System.out.println("A");
      }
      else{
        System.out.println("a");
    
      }
      
      
      
      

     
    }
   
    
       
    
}