import java.util.Scanner;
public class Main {
	public static void main(String[] args){
		
		Scanner in = new java.util.Scanner(System.in);
		String X = in.nextLine();

		if((short)X.charAt(0) >= (short)'a') {
			System.out.println('a');
		}else {
			System.out.println('A');
		}
		in.close();
	}
} import java.util.Scanner; Scanner java.util public class Main {
	public static void main(String[] args){
		
		Scanner in = new java.util.Scanner(System.in);
		String X = in.nextLine();

		if((short)X.charAt(0) >= (short)'a') {
			System.out.println('a');
		}else {
			System.out.println('A');
		}
		in.close();
	}
} Main public static void main(String[] args){
		
		Scanner in = new java.util.Scanner(System.in);
		String X = in.nextLine();

		if((short)X.charAt(0) >= (short)'a') {
			System.out.println('a');
		}else {
			System.out.println('A');
		}
		in.close();
	} main {
		
		Scanner in = new java.util.Scanner(System.in);
		String X = in.nextLine();

		if((short)X.charAt(0) >= (short)'a') {
			System.out.println('a');
		}else {
			System.out.println('A');
		}
		in.close();
	} Scanner in = new java.util.Scanner(System.in); in new java.util.Scanner(System.in) String X = in.nextLine(); X in.nextLine() in.nextLine in if((short)X.charAt(0) >= (short)'a') {
			System.out.println('a');
		}else {
			System.out.println('A');
		} (short)X.charAt(0) >= (short)'a' (short)X.charAt(0) X.charAt X 0 (short)'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' in.close() in.close in String[] args args public class Main {
	public static void main(String[] args){
		
		Scanner in = new java.util.Scanner(System.in);
		String X = in.nextLine();

		if((short)X.charAt(0) >= (short)'a') {
			System.out.println('a');
		}else {
			System.out.println('A');
		}
		in.close();
	}
} public class Main {
	public static void main(String[] args){
		
		Scanner in = new java.util.Scanner(System.in);
		String X = in.nextLine();

		if((short)X.charAt(0) >= (short)'a') {
			System.out.println('a');
		}else {
			System.out.println('A');
		}
		in.close();
	}
} Main
import java.util.Scanner;
public class Main {
	public static void main(String[] args){
		
		Scanner in = new java.util.Scanner(System.in);
		String X = in.nextLine();

		if((short)X.charAt(0) >= (short)'a') {
			System.out.println('a');
		}else {
			System.out.println('A');
		}
		in.close();
	}
}
