import java.util.Scanner;

public class Main {

	public static void main(String[] args) {

		Scanner scanner = new Scanner(System.in);
		String s= scanner.next();

		if (s.equals(s.toUpperCase())) {
			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);
		String s= scanner.next();

		if (s.equals(s.toUpperCase())) {
			System.out.println("A");
		} else {
			System.out.println("a");
		}

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

		Scanner scanner = new Scanner(System.in);
		String s= scanner.next();

		if (s.equals(s.toUpperCase())) {
			System.out.println("A");
		} else {
			System.out.println("a");
		}

	} main {

		Scanner scanner = new Scanner(System.in);
		String s= scanner.next();

		if (s.equals(s.toUpperCase())) {
			System.out.println("A");
		} else {
			System.out.println("a");
		}

	} Scanner scanner = new Scanner(System.in); scanner new Scanner(System.in) String s= scanner.next(); s scanner.next() scanner.next scanner if (s.equals(s.toUpperCase())) {
			System.out.println("A");
		} else {
			System.out.println("a");
		} s.equals(s.toUpperCase()) s.equals s s.toUpperCase() s.toUpperCase s {
			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 scanner = new Scanner(System.in);
		String s= scanner.next();

		if (s.equals(s.toUpperCase())) {
			System.out.println("A");
		} else {
			System.out.println("a");
		}

	}
} public class Main {

	public static void main(String[] args) {

		Scanner scanner = new Scanner(System.in);
		String s= scanner.next();

		if (s.equals(s.toUpperCase())) {
			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);
		String s= scanner.next();

		if (s.equals(s.toUpperCase())) {
			System.out.println("A");
		} else {
			System.out.println("a");
		}

	}
}
