import java.util.Scanner;

public class Main {
	
	public static void main(String[] args) {
		
		Scanner sc = new Scanner(System.in);
		
		String ch = sc.next();
		
		if(ch.charAt(0)>=65 && ch.charAt(0)<=90)
			System.out.println("A");
		
		else if(ch.charAt(0)>=97 && ch.charAt(0)<=122)
			System.out.println("a");
	}

} import java.util.Scanner; Scanner java.util public class Main {
	
	public static void main(String[] args) {
		
		Scanner sc = new Scanner(System.in);
		
		String ch = sc.next();
		
		if(ch.charAt(0)>=65 && ch.charAt(0)<=90)
			System.out.println("A");
		
		else if(ch.charAt(0)>=97 && ch.charAt(0)<=122)
			System.out.println("a");
	}

} Main public static void main(String[] args) {
		
		Scanner sc = new Scanner(System.in);
		
		String ch = sc.next();
		
		if(ch.charAt(0)>=65 && ch.charAt(0)<=90)
			System.out.println("A");
		
		else if(ch.charAt(0)>=97 && ch.charAt(0)<=122)
			System.out.println("a");
	} main {
		
		Scanner sc = new Scanner(System.in);
		
		String ch = sc.next();
		
		if(ch.charAt(0)>=65 && ch.charAt(0)<=90)
			System.out.println("A");
		
		else if(ch.charAt(0)>=97 && ch.charAt(0)<=122)
			System.out.println("a");
	} Scanner sc = new Scanner(System.in); sc new Scanner(System.in) String ch = sc.next(); ch sc.next() sc.next sc if(ch.charAt(0)>=65 && ch.charAt(0)<=90)
			System.out.println("A");
		
		else if(ch.charAt(0)>=97 && ch.charAt(0)<=122)
			System.out.println("a"); ch.charAt(0)>=65 && ch.charAt(0)<=90 ch.charAt(0)>=65 ch.charAt(0) ch.charAt ch 0 65 ch.charAt(0)<=90 ch.charAt(0) ch.charAt ch 0 90 System.out.println("A") System.out.println System.out System System.out "A" if(ch.charAt(0)>=97 && ch.charAt(0)<=122)
			System.out.println("a"); ch.charAt(0)>=97 && ch.charAt(0)<=122 ch.charAt(0)>=97 ch.charAt(0) ch.charAt ch 0 97 ch.charAt(0)<=122 ch.charAt(0) ch.charAt ch 0 122 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 sc = new Scanner(System.in);
		
		String ch = sc.next();
		
		if(ch.charAt(0)>=65 && ch.charAt(0)<=90)
			System.out.println("A");
		
		else if(ch.charAt(0)>=97 && ch.charAt(0)<=122)
			System.out.println("a");
	}

} public class Main {
	
	public static void main(String[] args) {
		
		Scanner sc = new Scanner(System.in);
		
		String ch = sc.next();
		
		if(ch.charAt(0)>=65 && ch.charAt(0)<=90)
			System.out.println("A");
		
		else if(ch.charAt(0)>=97 && ch.charAt(0)<=122)
			System.out.println("a");
	}

} Main
import java.util.Scanner;

public class Main {
	
	public static void main(String[] args) {
		
		Scanner sc = new Scanner(System.in);
		
		String ch = sc.next();
		
		if(ch.charAt(0)>=65 && ch.charAt(0)<=90)
			System.out.println("A");
		
		else if(ch.charAt(0)>=97 && ch.charAt(0)<=122)
			System.out.println("a");
	}

}