import java.io.IOException;
import java.util.Scanner;

public class Main {
	public static void main(String[] args) throws IOException{
		Scanner scan = new Scanner(System.in);
		String str = scan.next();
		if(Character.isUpperCase(str.charAt(0))){
			System.out.println("A");
		}else {
			System.out.println("a");
		}
	}
} import java.io.IOException; IOException java.io import java.util.Scanner; Scanner java.util public class Main {
	public static void main(String[] args) throws IOException{
		Scanner scan = new Scanner(System.in);
		String str = scan.next();
		if(Character.isUpperCase(str.charAt(0))){
			System.out.println("A");
		}else {
			System.out.println("a");
		}
	}
} Main public static void main(String[] args) throws IOException{
		Scanner scan = new Scanner(System.in);
		String str = scan.next();
		if(Character.isUpperCase(str.charAt(0))){
			System.out.println("A");
		}else {
			System.out.println("a");
		}
	} main {
		Scanner scan = new Scanner(System.in);
		String str = scan.next();
		if(Character.isUpperCase(str.charAt(0))){
			System.out.println("A");
		}else {
			System.out.println("a");
		}
	} Scanner scan = new Scanner(System.in); scan new Scanner(System.in) String str = scan.next(); str scan.next() scan.next scan if(Character.isUpperCase(str.charAt(0))){
			System.out.println("A");
		}else {
			System.out.println("a");
		} Character.isUpperCase(str.charAt(0)) Character.isUpperCase Character str.charAt(0) str.charAt str 0 {
			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" String[] args args public class Main {
	public static void main(String[] args) throws IOException{
		Scanner scan = new Scanner(System.in);
		String str = scan.next();
		if(Character.isUpperCase(str.charAt(0))){
			System.out.println("A");
		}else {
			System.out.println("a");
		}
	}
} public class Main {
	public static void main(String[] args) throws IOException{
		Scanner scan = new Scanner(System.in);
		String str = scan.next();
		if(Character.isUpperCase(str.charAt(0))){
			System.out.println("A");
		}else {
			System.out.println("a");
		}
	}
} Main
import java.io.IOException;
import java.util.Scanner;

public class Main {
	public static void main(String[] args) throws IOException{
		Scanner scan = new Scanner(System.in);
		String str = scan.next();
		if(Character.isUpperCase(str.charAt(0))){
			System.out.println("A");
		}else {
			System.out.println("a");
		}
	}
}