import java.util.Scanner;

// ABC171-A
public class Main {

	public static void main(String[] args) {

		Scanner sc = new Scanner(System.in);
		String input = sc.next();
		char alphabet = input.charAt(0);

		if (Character.isUpperCase(alphabet)) {
			System.out.println('A');
		} else {
			System.out.println('a');
		}

		sc.close();
	}
} import java.util.Scanner; Scanner java.util public class Main {

	public static void main(String[] args) {

		Scanner sc = new Scanner(System.in);
		String input = sc.next();
		char alphabet = input.charAt(0);

		if (Character.isUpperCase(alphabet)) {
			System.out.println('A');
		} else {
			System.out.println('a');
		}

		sc.close();
	}
} Main public static void main(String[] args) {

		Scanner sc = new Scanner(System.in);
		String input = sc.next();
		char alphabet = input.charAt(0);

		if (Character.isUpperCase(alphabet)) {
			System.out.println('A');
		} else {
			System.out.println('a');
		}

		sc.close();
	} main {

		Scanner sc = new Scanner(System.in);
		String input = sc.next();
		char alphabet = input.charAt(0);

		if (Character.isUpperCase(alphabet)) {
			System.out.println('A');
		} else {
			System.out.println('a');
		}

		sc.close();
	} Scanner sc = new Scanner(System.in); sc new Scanner(System.in) String input = sc.next(); input sc.next() sc.next sc char alphabet = input.charAt(0); alphabet input.charAt(0) input.charAt input 0 if (Character.isUpperCase(alphabet)) {
			System.out.println('A');
		} else {
			System.out.println('a');
		} Character.isUpperCase(alphabet) Character.isUpperCase Character alphabet {
			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' sc.close() sc.close sc String[] args args public class Main {

	public static void main(String[] args) {

		Scanner sc = new Scanner(System.in);
		String input = sc.next();
		char alphabet = input.charAt(0);

		if (Character.isUpperCase(alphabet)) {
			System.out.println('A');
		} else {
			System.out.println('a');
		}

		sc.close();
	}
} public class Main {

	public static void main(String[] args) {

		Scanner sc = new Scanner(System.in);
		String input = sc.next();
		char alphabet = input.charAt(0);

		if (Character.isUpperCase(alphabet)) {
			System.out.println('A');
		} else {
			System.out.println('a');
		}

		sc.close();
	}
} Main
import java.util.Scanner;

// ABC171-A
public class Main {

	public static void main(String[] args) {

		Scanner sc = new Scanner(System.in);
		String input = sc.next();
		char alphabet = input.charAt(0);

		if (Character.isUpperCase(alphabet)) {
			System.out.println('A');
		} else {
			System.out.println('a');
		}

		sc.close();
	}
}
