import java.util.Scanner;
public class Main {
	int d,k;
	public void solve() {
	Scanner sc = new Scanner(System.in);
	String a = sc.next();

	if( Character.isUpperCase( a.charAt( 0 ) ) ) {
	    System.out.println("A");
	}else {
	    System.out.println("a");
	}
	}
	public static void main(String[] args) {
		new Main().solve();
	
	}
} import java.util.Scanner; Scanner java.util public class Main {
	int d,k;
	public void solve() {
	Scanner sc = new Scanner(System.in);
	String a = sc.next();

	if( Character.isUpperCase( a.charAt( 0 ) ) ) {
	    System.out.println("A");
	}else {
	    System.out.println("a");
	}
	}
	public static void main(String[] args) {
		new Main().solve();
	
	}
} Main int d d k; k public void solve() {
	Scanner sc = new Scanner(System.in);
	String a = sc.next();

	if( Character.isUpperCase( a.charAt( 0 ) ) ) {
	    System.out.println("A");
	}else {
	    System.out.println("a");
	}
	} solve {
	Scanner sc = new Scanner(System.in);
	String a = sc.next();

	if( Character.isUpperCase( a.charAt( 0 ) ) ) {
	    System.out.println("A");
	}else {
	    System.out.println("a");
	}
	} Scanner sc = new Scanner(System.in); sc new Scanner(System.in) String a = sc.next(); a sc.next() sc.next sc if( Character.isUpperCase( a.charAt( 0 ) ) ) {
	    System.out.println("A");
	}else {
	    System.out.println("a");
	} Character.isUpperCase( a.charAt( 0 ) ) Character.isUpperCase Character a.charAt( 0 ) a.charAt a 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" public static void main(String[] args) {
		new Main().solve();
	
	} main {
		new Main().solve();
	
	} new Main().solve() new Main().solve new Main() String[] args args public class Main {
	int d,k;
	public void solve() {
	Scanner sc = new Scanner(System.in);
	String a = sc.next();

	if( Character.isUpperCase( a.charAt( 0 ) ) ) {
	    System.out.println("A");
	}else {
	    System.out.println("a");
	}
	}
	public static void main(String[] args) {
		new Main().solve();
	
	}
} public class Main {
	int d,k;
	public void solve() {
	Scanner sc = new Scanner(System.in);
	String a = sc.next();

	if( Character.isUpperCase( a.charAt( 0 ) ) ) {
	    System.out.println("A");
	}else {
	    System.out.println("a");
	}
	}
	public static void main(String[] args) {
		new Main().solve();
	
	}
} Main
import java.util.Scanner;
public class Main {
	int d,k;
	public void solve() {
	Scanner sc = new Scanner(System.in);
	String a = sc.next();

	if( Character.isUpperCase( a.charAt( 0 ) ) ) {
	    System.out.println("A");
	}else {
	    System.out.println("a");
	}
	}
	public static void main(String[] args) {
		new Main().solve();
	
	}
}
