import java.util.Scanner;
public class Main {

	public static void main(String[] args) {
		Scanner scan = new Scanner(System.in);
		String a = scan.next();
		if(Character.isUpperCase( a.charAt(0))) {
			System.out.print("A");
		}
		else {
			System.out.print("a");
		}
	}

} import java.util.Scanner; Scanner java.util public class Main {

	public static void main(String[] args) {
		Scanner scan = new Scanner(System.in);
		String a = scan.next();
		if(Character.isUpperCase( a.charAt(0))) {
			System.out.print("A");
		}
		else {
			System.out.print("a");
		}
	}

} Main public static void main(String[] args) {
		Scanner scan = new Scanner(System.in);
		String a = scan.next();
		if(Character.isUpperCase( a.charAt(0))) {
			System.out.print("A");
		}
		else {
			System.out.print("a");
		}
	} main {
		Scanner scan = new Scanner(System.in);
		String a = scan.next();
		if(Character.isUpperCase( a.charAt(0))) {
			System.out.print("A");
		}
		else {
			System.out.print("a");
		}
	} Scanner scan = new Scanner(System.in); scan new Scanner(System.in) String a = scan.next(); a scan.next() scan.next scan if(Character.isUpperCase( a.charAt(0))) {
			System.out.print("A");
		}
		else {
			System.out.print("a");
		} Character.isUpperCase( a.charAt(0)) Character.isUpperCase Character a.charAt(0) a.charAt a 0 {
			System.out.print("A");
		} System.out.print("A") System.out.print System.out System System.out "A" {
			System.out.print("a");
		} System.out.print("a") System.out.print System.out System System.out "a" String[] args args public class Main {

	public static void main(String[] args) {
		Scanner scan = new Scanner(System.in);
		String a = scan.next();
		if(Character.isUpperCase( a.charAt(0))) {
			System.out.print("A");
		}
		else {
			System.out.print("a");
		}
	}

} public class Main {

	public static void main(String[] args) {
		Scanner scan = new Scanner(System.in);
		String a = scan.next();
		if(Character.isUpperCase( a.charAt(0))) {
			System.out.print("A");
		}
		else {
			System.out.print("a");
		}
	}

} Main
import java.util.Scanner;
public class Main {

	public static void main(String[] args) {
		Scanner scan = new Scanner(System.in);
		String a = scan.next();
		if(Character.isUpperCase( a.charAt(0))) {
			System.out.print("A");
		}
		else {
			System.out.print("a");
		}
	}

}