import java.util.Scanner;


public class Main {

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

	public static void main(String[] args)  {
		Scanner sc = new Scanner(System.in);
		char ans = sc.next().charAt(0);
		if(ans < 'a') {
			System.out.println("A");
		}else{
			System.out.println("a");
		}
	}
} Main
import java.util.Scanner;


public class Main {

	public static void main(String[] args)  {
		Scanner sc = new Scanner(System.in);
		char ans = sc.next().charAt(0);
		if(ans < 'a') {
			System.out.println("A");
		}else{
			System.out.println("a");
		}
	}
}


