import java.util.*;

public class Main {
    public static void main(String args[]){
        Scanner stdIn = new Scanner(System.in);
        String s = stdIn.next();
        String ss = s.toUpperCase();
        //boolean flag = true;
        
        if(s.equals(ss)){
            System.out.println("A");
        }else{
            System.out.println("a");
        }
    }
} import java.util.*; util.* java public class Main {
    public static void main(String args[]){
        Scanner stdIn = new Scanner(System.in);
        String s = stdIn.next();
        String ss = s.toUpperCase();
        //boolean flag = true;
        
        if(s.equals(ss)){
            System.out.println("A");
        }else{
            System.out.println("a");
        }
    }
} Main public static void main(String args[]){
        Scanner stdIn = new Scanner(System.in);
        String s = stdIn.next();
        String ss = s.toUpperCase();
        //boolean flag = true;
        
        if(s.equals(ss)){
            System.out.println("A");
        }else{
            System.out.println("a");
        }
    } main {
        Scanner stdIn = new Scanner(System.in);
        String s = stdIn.next();
        String ss = s.toUpperCase();
        //boolean flag = true;
        
        if(s.equals(ss)){
            System.out.println("A");
        }else{
            System.out.println("a");
        }
    } Scanner stdIn = new Scanner(System.in); stdIn new Scanner(System.in) String s = stdIn.next(); s stdIn.next() stdIn.next stdIn String ss = s.toUpperCase(); ss s.toUpperCase() s.toUpperCase s if(s.equals(ss)){
            System.out.println("A");
        }else{
            System.out.println("a");
        } s.equals(ss) s.equals s ss {
            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 stdIn = new Scanner(System.in);
        String s = stdIn.next();
        String ss = s.toUpperCase();
        //boolean flag = true;
        
        if(s.equals(ss)){
            System.out.println("A");
        }else{
            System.out.println("a");
        }
    }
} public class Main {
    public static void main(String args[]){
        Scanner stdIn = new Scanner(System.in);
        String s = stdIn.next();
        String ss = s.toUpperCase();
        //boolean flag = true;
        
        if(s.equals(ss)){
            System.out.println("A");
        }else{
            System.out.println("a");
        }
    }
} Main
import java.util.*;

public class Main {
    public static void main(String args[]){
        Scanner stdIn = new Scanner(System.in);
        String s = stdIn.next();
        String ss = s.toUpperCase();
        //boolean flag = true;
        
        if(s.equals(ss)){
            System.out.println("A");
        }else{
            System.out.println("a");
        }
    }
}
