import java.util.Scanner;

public class Main {
	public static void main(String[] args) {
		Scanner scanner = new Scanner(System.in);
		String letter = scanner.next();
		char a = 'a';
		
		if(letter.equals(letter.toUpperCase()))
			a = 'A';
		System.out.print(a);
	}
} import java.util.Scanner; Scanner java.util public class Main {
	public static void main(String[] args) {
		Scanner scanner = new Scanner(System.in);
		String letter = scanner.next();
		char a = 'a';
		
		if(letter.equals(letter.toUpperCase()))
			a = 'A';
		System.out.print(a);
	}
} Main public static void main(String[] args) {
		Scanner scanner = new Scanner(System.in);
		String letter = scanner.next();
		char a = 'a';
		
		if(letter.equals(letter.toUpperCase()))
			a = 'A';
		System.out.print(a);
	} main {
		Scanner scanner = new Scanner(System.in);
		String letter = scanner.next();
		char a = 'a';
		
		if(letter.equals(letter.toUpperCase()))
			a = 'A';
		System.out.print(a);
	} Scanner scanner = new Scanner(System.in); scanner new Scanner(System.in) String letter = scanner.next(); letter scanner.next() scanner.next scanner char a = 'a'; a 'a' if(letter.equals(letter.toUpperCase()))
			a = 'A'; letter.equals(letter.toUpperCase()) letter.equals letter letter.toUpperCase() letter.toUpperCase letter a = 'A' a '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 scanner = new Scanner(System.in);
		String letter = scanner.next();
		char a = 'a';
		
		if(letter.equals(letter.toUpperCase()))
			a = 'A';
		System.out.print(a);
	}
} public class Main {
	public static void main(String[] args) {
		Scanner scanner = new Scanner(System.in);
		String letter = scanner.next();
		char a = 'a';
		
		if(letter.equals(letter.toUpperCase()))
			a = 'A';
		System.out.print(a);
	}
} Main
import java.util.Scanner;

public class Main {
	public static void main(String[] args) {
		Scanner scanner = new Scanner(System.in);
		String letter = scanner.next();
		char a = 'a';
		
		if(letter.equals(letter.toUpperCase()))
			a = 'A';
		System.out.print(a);
	}
}
