import java.math.BigDecimal;
import java.time.LocalDate;
import java.util.ArrayList;
import java.util.Arrays;
import java.util.Date;
import java.util.HashMap;
import java.util.List;
import java.util.Map;
import java.util.Scanner;
import java.util.concurrent.CountDownLatch;

public class Main {

	public static void main(String args[]) {

		Scanner scanner = new Scanner(System.in);

		String aString =  scanner.next();
		
		
		if(aString.charAt(0) >= 97 ) {
			System.out.println("a");
		} else {
			System.out.println("A");
		}
		
		
	}} import java.math.BigDecimal; BigDecimal java.math import java.time.LocalDate; LocalDate java.time import java.util.ArrayList; ArrayList java.util import java.util.Arrays; Arrays java.util import java.util.Date; Date java.util import java.util.HashMap; HashMap java.util import java.util.List; List java.util import java.util.Map; Map java.util import java.util.Scanner; Scanner java.util import java.util.concurrent.CountDownLatch; CountDownLatch java.util.concurrent public class Main {

	public static void main(String args[]) {

		Scanner scanner = new Scanner(System.in);

		String aString =  scanner.next();
		
		
		if(aString.charAt(0) >= 97 ) {
			System.out.println("a");
		} else {
			System.out.println("A");
		}
		
		
	}} Main public static void main(String args[]) {

		Scanner scanner = new Scanner(System.in);

		String aString =  scanner.next();
		
		
		if(aString.charAt(0) >= 97 ) {
			System.out.println("a");
		} else {
			System.out.println("A");
		}
		
		
	} main {

		Scanner scanner = new Scanner(System.in);

		String aString =  scanner.next();
		
		
		if(aString.charAt(0) >= 97 ) {
			System.out.println("a");
		} else {
			System.out.println("A");
		}
		
		
	} Scanner scanner = new Scanner(System.in); scanner new Scanner(System.in) String aString =  scanner.next(); aString scanner.next() scanner.next scanner if(aString.charAt(0) >= 97 ) {
			System.out.println("a");
		} else {
			System.out.println("A");
		} aString.charAt(0) >= 97 aString.charAt(0) aString.charAt aString 0 97 {
			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[]) {

		Scanner scanner = new Scanner(System.in);

		String aString =  scanner.next();
		
		
		if(aString.charAt(0) >= 97 ) {
			System.out.println("a");
		} else {
			System.out.println("A");
		}
		
		
	}} public class Main {

	public static void main(String args[]) {

		Scanner scanner = new Scanner(System.in);

		String aString =  scanner.next();
		
		
		if(aString.charAt(0) >= 97 ) {
			System.out.println("a");
		} else {
			System.out.println("A");
		}
		
		
	}} Main
import java.math.BigDecimal;
import java.time.LocalDate;
import java.util.ArrayList;
import java.util.Arrays;
import java.util.Date;
import java.util.HashMap;
import java.util.List;
import java.util.Map;
import java.util.Scanner;
import java.util.concurrent.CountDownLatch;

public class Main {

	public static void main(String args[]) {

		Scanner scanner = new Scanner(System.in);

		String aString =  scanner.next();
		
		
		if(aString.charAt(0) >= 97 ) {
			System.out.println("a");
		} else {
			System.out.println("A");
		}
		
		
	}}