import java.util.*;

public class Main{
	public static void main(String[] args) {
		
		
		Scanner sc = new Scanner(System.in);

		String output = sc.next();
		char validate = output.charAt(0);

		if(Character.isUpperCase(validate)){
			output = "A";
		}else {
			output ="a";
		}
		
		System.out.println(output);
	}
} import java.util.*; util.* java public class Main{
	public static void main(String[] args) {
		
		
		Scanner sc = new Scanner(System.in);

		String output = sc.next();
		char validate = output.charAt(0);

		if(Character.isUpperCase(validate)){
			output = "A";
		}else {
			output ="a";
		}
		
		System.out.println(output);
	}
} Main public static void main(String[] args) {
		
		
		Scanner sc = new Scanner(System.in);

		String output = sc.next();
		char validate = output.charAt(0);

		if(Character.isUpperCase(validate)){
			output = "A";
		}else {
			output ="a";
		}
		
		System.out.println(output);
	} main {
		
		
		Scanner sc = new Scanner(System.in);

		String output = sc.next();
		char validate = output.charAt(0);

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

		String output = sc.next();
		char validate = output.charAt(0);

		if(Character.isUpperCase(validate)){
			output = "A";
		}else {
			output ="a";
		}
		
		System.out.println(output);
	}
} public class Main{
	public static void main(String[] args) {
		
		
		Scanner sc = new Scanner(System.in);

		String output = sc.next();
		char validate = output.charAt(0);

		if(Character.isUpperCase(validate)){
			output = "A";
		}else {
			output ="a";
		}
		
		System.out.println(output);
	}
} Main
import java.util.*;

public class Main{
	public static void main(String[] args) {
		
		
		Scanner sc = new Scanner(System.in);

		String output = sc.next();
		char validate = output.charAt(0);

		if(Character.isUpperCase(validate)){
			output = "A";
		}else {
			output ="a";
		}
		
		System.out.println(output);
	}
}