import java.util.*;
public class Main {
    public static void main(String[] args){
    
    Scanner sc = new Scanner(System.in);
        String S = sc.next();
        char[]ss = S.toCharArray();
        
        if(ss[0]-0<91){
            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 S = sc.next();
        char[]ss = S.toCharArray();
        
        if(ss[0]-0<91){
            System.out.println('A');
        }else{
        System.out.println('a');
        }
    }         
} Main public static void main(String[] args){
    
    Scanner sc = new Scanner(System.in);
        String S = sc.next();
        char[]ss = S.toCharArray();
        
        if(ss[0]-0<91){
            System.out.println('A');
        }else{
        System.out.println('a');
        }
    } main {
    
    Scanner sc = new Scanner(System.in);
        String S = sc.next();
        char[]ss = S.toCharArray();
        
        if(ss[0]-0<91){
            System.out.println('A');
        }else{
        System.out.println('a');
        }
    } Scanner sc = new Scanner(System.in); sc new Scanner(System.in) String S = sc.next(); S sc.next() sc.next sc char[]ss = S.toCharArray(); ss S.toCharArray() S.toCharArray S if(ss[0]-0<91){
            System.out.println('A');
        }else{
        System.out.println('a');
        } ss[0]-0<91 ss[0]-0 ss[0] ss 0 0 91 {
            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 S = sc.next();
        char[]ss = S.toCharArray();
        
        if(ss[0]-0<91){
            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 S = sc.next();
        char[]ss = S.toCharArray();
        
        if(ss[0]-0<91){
            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 S = sc.next();
        char[]ss = S.toCharArray();
        
        if(ss[0]-0<91){
            System.out.println('A');
        }else{
        System.out.println('a');
        }
    }         
}
