import java.util.*;
public class Main{
   public static void main(String[] args) {
     Scanner sc = new Scanner(System.in);
     String  n = sc.next();
     char[] alpha = n.toCharArray();
     char check = 'A';
     char Check = 'Z';
     if(check<=alpha[0] && alpha[0]<=Check){
       System.out.println('A');
     }else{
       System.out.println('a');
     }

   }
} import java.util.*; util.* java public class Main{
   public static void main(String[] args) {
     Scanner sc = new Scanner(System.in);
     String  n = sc.next();
     char[] alpha = n.toCharArray();
     char check = 'A';
     char Check = 'Z';
     if(check<=alpha[0] && alpha[0]<=Check){
       System.out.println('A');
     }else{
       System.out.println('a');
     }

   }
} Main public static void main(String[] args) {
     Scanner sc = new Scanner(System.in);
     String  n = sc.next();
     char[] alpha = n.toCharArray();
     char check = 'A';
     char Check = 'Z';
     if(check<=alpha[0] && alpha[0]<=Check){
       System.out.println('A');
     }else{
       System.out.println('a');
     }

   } main {
     Scanner sc = new Scanner(System.in);
     String  n = sc.next();
     char[] alpha = n.toCharArray();
     char check = 'A';
     char Check = 'Z';
     if(check<=alpha[0] && alpha[0]<=Check){
       System.out.println('A');
     }else{
       System.out.println('a');
     }

   } Scanner sc = new Scanner(System.in); sc new Scanner(System.in) String  n = sc.next(); n sc.next() sc.next sc char[] alpha = n.toCharArray(); alpha n.toCharArray() n.toCharArray n char check = 'A'; check 'A' char Check = 'Z'; Check 'Z' if(check<=alpha[0] && alpha[0]<=Check){
       System.out.println('A');
     }else{
       System.out.println('a');
     } check<=alpha[0] && alpha[0]<=Check check<=alpha[0] check alpha[0] alpha 0 alpha[0]<=Check alpha[0] alpha 0 Check {
       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  n = sc.next();
     char[] alpha = n.toCharArray();
     char check = 'A';
     char Check = 'Z';
     if(check<=alpha[0] && alpha[0]<=Check){
       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  n = sc.next();
     char[] alpha = n.toCharArray();
     char check = 'A';
     char Check = 'Z';
     if(check<=alpha[0] && alpha[0]<=Check){
       System.out.println('A');
     }else{
       System.out.println('a');
     }

   }
} Main
import java.util.*;
public class Main{
   public static void main(String[] args) {
     Scanner sc = new Scanner(System.in);
     String  n = sc.next();
     char[] alpha = n.toCharArray();
     char check = 'A';
     char Check = 'Z';
     if(check<=alpha[0] && alpha[0]<=Check){
       System.out.println('A');
     }else{
       System.out.println('a');
     }

   }
}
