import java.util.Scanner;

public class Main{
    public static void main(String[] args){
        Scanner sc = new Scanner(System.in);

        String str = sc.next();
        if(str.matches("[A-Z]")){
            System.out.println("A");
        }
        else{
            System.out.println("a");
        }
    }
} import java.util.Scanner; Scanner java.util public class Main{
    public static void main(String[] args){
        Scanner sc = new Scanner(System.in);

        String str = sc.next();
        if(str.matches("[A-Z]")){
            System.out.println("A");
        }
        else{
            System.out.println("a");
        }
    }
} Main public static void main(String[] args){
        Scanner sc = new Scanner(System.in);

        String str = sc.next();
        if(str.matches("[A-Z]")){
            System.out.println("A");
        }
        else{
            System.out.println("a");
        }
    } main {
        Scanner sc = new Scanner(System.in);

        String str = sc.next();
        if(str.matches("[A-Z]")){
            System.out.println("A");
        }
        else{
            System.out.println("a");
        }
    } Scanner sc = new Scanner(System.in); sc new Scanner(System.in) String str = sc.next(); str sc.next() sc.next sc if(str.matches("[A-Z]")){
            System.out.println("A");
        }
        else{
            System.out.println("a");
        } str.matches("[A-Z]") str.matches str "[A-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);

        String str = sc.next();
        if(str.matches("[A-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);

        String str = sc.next();
        if(str.matches("[A-Z]")){
            System.out.println("A");
        }
        else{
            System.out.println("a");
        }
    }
} Main
import java.util.Scanner;

public class Main{
    public static void main(String[] args){
        Scanner sc = new Scanner(System.in);

        String str = sc.next();
        if(str.matches("[A-Z]")){
            System.out.println("A");
        }
        else{
            System.out.println("a");
        }
    }
}