import java.util.Scanner;

public class Main {
	
	public static void main(String[] args) {
		Scanner s = new Scanner(System.in);
		char c = s.next().charAt(0);
		
		if(c>=65 && c<=90) {
			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 s = new Scanner(System.in);
		char c = s.next().charAt(0);
		
		if(c>=65 && c<=90) {
			System.out.println("A");
		}
		else
			System.out.println('a');
	}

} Main public static void main(String[] args) {
		Scanner s = new Scanner(System.in);
		char c = s.next().charAt(0);
		
		if(c>=65 && c<=90) {
			System.out.println("A");
		}
		else
			System.out.println('a');
	} main {
		Scanner s = new Scanner(System.in);
		char c = s.next().charAt(0);
		
		if(c>=65 && c<=90) {
			System.out.println("A");
		}
		else
			System.out.println('a');
	} Scanner s = new Scanner(System.in); s new Scanner(System.in) char c = s.next().charAt(0); c s.next().charAt(0) s.next().charAt s.next() s.next s 0 if(c>=65 && c<=90) {
			System.out.println("A");
		}
		else
			System.out.println('a'); c>=65 && c<=90 c>=65 c 65 c<=90 c 90 {
			System.out.println("A");
		} System.out.println("A") System.out.println System.out System System.out "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 s = new Scanner(System.in);
		char c = s.next().charAt(0);
		
		if(c>=65 && c<=90) {
			System.out.println("A");
		}
		else
			System.out.println('a');
	}

} public class Main {
	
	public static void main(String[] args) {
		Scanner s = new Scanner(System.in);
		char c = s.next().charAt(0);
		
		if(c>=65 && c<=90) {
			System.out.println("A");
		}
		else
			System.out.println('a');
	}

} Main
import java.util.Scanner;

public class Main {
	
	public static void main(String[] args) {
		Scanner s = new Scanner(System.in);
		char c = s.next().charAt(0);
		
		if(c>=65 && c<=90) {
			System.out.println("A");
		}
		else
			System.out.println('a');
	}

}
