import java.util.Scanner;
public class Main {

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

	}

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

	} main {
		Scanner scan = new Scanner(System.in);
		String alpha = scan.next();
		
		if(Character.isUpperCase(alpha.charAt(0))) {
			System.out.println("A");
		}else {
			System.out.println("a");
		}

	} Scanner scan = new Scanner(System.in); scan new Scanner(System.in) String alpha = scan.next(); alpha scan.next() scan.next scan if(Character.isUpperCase(alpha.charAt(0))) {
			System.out.println("A");
		}else {
			System.out.println("a");
		} Character.isUpperCase(alpha.charAt(0)) Character.isUpperCase Character alpha.charAt(0) alpha.charAt alpha 0 {
			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 scan = new Scanner(System.in);
		String alpha = scan.next();
		
		if(Character.isUpperCase(alpha.charAt(0))) {
			System.out.println("A");
		}else {
			System.out.println("a");
		}

	}

} public class Main {

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

	}

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

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

	}

}
