import java.util.Scanner;

public class Main {

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

		if (s.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 s = sc.nextLine();

		if (s.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 s = sc.nextLine();

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

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

		if (s.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 s = sc.nextLine();

		if (s.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 s = sc.nextLine();

		if (s.matches("[A-Z]")) {
			System.out.println("A");
		} else {
			System.out.println("a");
		}
	}
}
