import java.util.Scanner;

public class Main {

	public static void main(final String[] args) {
		Scanner sc = new Scanner(System.in);
		Character character = sc.next().charAt(0);
		if (character >= 'a' && character <= 'z') {
			System.out.println("a");
		}else {
			System.out.println("A");
		}
	}
} import java.util.Scanner; Scanner java.util public class Main {

	public static void main(final String[] args) {
		Scanner sc = new Scanner(System.in);
		Character character = sc.next().charAt(0);
		if (character >= 'a' && character <= 'z') {
			System.out.println("a");
		}else {
			System.out.println("A");
		}
	}
} Main public static void main(final String[] args) {
		Scanner sc = new Scanner(System.in);
		Character character = sc.next().charAt(0);
		if (character >= 'a' && character <= 'z') {
			System.out.println("a");
		}else {
			System.out.println("A");
		}
	} main {
		Scanner sc = new Scanner(System.in);
		Character character = sc.next().charAt(0);
		if (character >= 'a' && character <= 'z') {
			System.out.println("a");
		}else {
			System.out.println("A");
		}
	} Scanner sc = new Scanner(System.in); sc new Scanner(System.in) Character character = sc.next().charAt(0); character sc.next().charAt(0) sc.next().charAt sc.next() sc.next sc 0 if (character >= 'a' && character <= 'z') {
			System.out.println("a");
		}else {
			System.out.println("A");
		} character >= 'a' && character <= 'z' character >= 'a' character 'a' character <= 'z' character '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" final String[] args args public class Main {

	public static void main(final String[] args) {
		Scanner sc = new Scanner(System.in);
		Character character = sc.next().charAt(0);
		if (character >= 'a' && character <= 'z') {
			System.out.println("a");
		}else {
			System.out.println("A");
		}
	}
} public class Main {

	public static void main(final String[] args) {
		Scanner sc = new Scanner(System.in);
		Character character = sc.next().charAt(0);
		if (character >= 'a' && character <= 'z') {
			System.out.println("a");
		}else {
			System.out.println("A");
		}
	}
} Main
import java.util.Scanner;

public class Main {

	public static void main(final String[] args) {
		Scanner sc = new Scanner(System.in);
		Character character = sc.next().charAt(0);
		if (character >= 'a' && character <= 'z') {
			System.out.println("a");
		}else {
			System.out.println("A");
		}
	}
}
