import java.util.Scanner;

public class Main {


    public static void main(String[] args) {

        Scanner scanner = new Scanner(System.in);
        char c = scanner.nextLine().charAt(0);
        if (Character.isLowerCase(c))
            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 scanner = new Scanner(System.in);
        char c = scanner.nextLine().charAt(0);
        if (Character.isLowerCase(c))
            System.out.println('a');
        else 
            System.out.println('A');


    }
} Main public static void main(String[] args) {

        Scanner scanner = new Scanner(System.in);
        char c = scanner.nextLine().charAt(0);
        if (Character.isLowerCase(c))
            System.out.println('a');
        else 
            System.out.println('A');


    } main {

        Scanner scanner = new Scanner(System.in);
        char c = scanner.nextLine().charAt(0);
        if (Character.isLowerCase(c))
            System.out.println('a');
        else 
            System.out.println('A');


    } Scanner scanner = new Scanner(System.in); scanner new Scanner(System.in) char c = scanner.nextLine().charAt(0); c scanner.nextLine().charAt(0) scanner.nextLine().charAt scanner.nextLine() scanner.nextLine scanner 0 if (Character.isLowerCase(c))
            System.out.println('a');
        else 
            System.out.println('A'); Character.isLowerCase(c) Character.isLowerCase Character c System.out.println('a') System.out.println System.out System System.out '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 scanner = new Scanner(System.in);
        char c = scanner.nextLine().charAt(0);
        if (Character.isLowerCase(c))
            System.out.println('a');
        else 
            System.out.println('A');


    }
} public class Main {


    public static void main(String[] args) {

        Scanner scanner = new Scanner(System.in);
        char c = scanner.nextLine().charAt(0);
        if (Character.isLowerCase(c))
            System.out.println('a');
        else 
            System.out.println('A');


    }
} Main
import java.util.Scanner;

public class Main {


    public static void main(String[] args) {

        Scanner scanner = new Scanner(System.in);
        char c = scanner.nextLine().charAt(0);
        if (Character.isLowerCase(c))
            System.out.println('a');
        else 
            System.out.println('A');


    }
}
