import java.util.Scanner;

public class Main {

	public static void main(String[] args) {
		// TODO Auto-generated method stub
		Scanner scn = new Scanner(System.in);
		String s = scn.next();
		boolean check = Character.isUpperCase(s.charAt(0));
		if (check) {
			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) {
		// TODO Auto-generated method stub
		Scanner scn = new Scanner(System.in);
		String s = scn.next();
		boolean check = Character.isUpperCase(s.charAt(0));
		if (check) {
			System.out.println("A");
		} else {
			System.out.println("a");
		}
	}

} Main public static void main(String[] args) {
		// TODO Auto-generated method stub
		Scanner scn = new Scanner(System.in);
		String s = scn.next();
		boolean check = Character.isUpperCase(s.charAt(0));
		if (check) {
			System.out.println("A");
		} else {
			System.out.println("a");
		}
	} main {
		// TODO Auto-generated method stub
		Scanner scn = new Scanner(System.in);
		String s = scn.next();
		boolean check = Character.isUpperCase(s.charAt(0));
		if (check) {
			System.out.println("A");
		} else {
			System.out.println("a");
		}
	} Scanner scn = new Scanner(System.in); scn new Scanner(System.in) String s = scn.next(); s scn.next() scn.next scn boolean check = Character.isUpperCase(s.charAt(0)); check Character.isUpperCase(s.charAt(0)) Character.isUpperCase Character s.charAt(0) s.charAt s 0 if (check) {
			System.out.println("A");
		} else {
			System.out.println("a");
		} check {
			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) {
		// TODO Auto-generated method stub
		Scanner scn = new Scanner(System.in);
		String s = scn.next();
		boolean check = Character.isUpperCase(s.charAt(0));
		if (check) {
			System.out.println("A");
		} else {
			System.out.println("a");
		}
	}

} public class Main {

	public static void main(String[] args) {
		// TODO Auto-generated method stub
		Scanner scn = new Scanner(System.in);
		String s = scn.next();
		boolean check = Character.isUpperCase(s.charAt(0));
		if (check) {
			System.out.println("A");
		} else {
			System.out.println("a");
		}
	}

} Main
import java.util.Scanner;

public class Main {

	public static void main(String[] args) {
		// TODO Auto-generated method stub
		Scanner scn = new Scanner(System.in);
		String s = scn.next();
		boolean check = Character.isUpperCase(s.charAt(0));
		if (check) {
			System.out.println("A");
		} else {
			System.out.println("a");
		}
	}

}
