import java.util.*;
public class Main{
	public static void main(String[] args) {
		Scanner in=new Scanner(System.in);
		if(Character.isUpperCase(in.next().charAt(0)))
			System.out.println('A');
		else
			System.out.println('a');
	}
} import java.util.*; util.* java public class Main{
	public static void main(String[] args) {
		Scanner in=new Scanner(System.in);
		if(Character.isUpperCase(in.next().charAt(0)))
			System.out.println('A');
		else
			System.out.println('a');
	}
} Main public static void main(String[] args) {
		Scanner in=new Scanner(System.in);
		if(Character.isUpperCase(in.next().charAt(0)))
			System.out.println('A');
		else
			System.out.println('a');
	} main {
		Scanner in=new Scanner(System.in);
		if(Character.isUpperCase(in.next().charAt(0)))
			System.out.println('A');
		else
			System.out.println('a');
	} Scanner in=new Scanner(System.in); in new Scanner(System.in) if(Character.isUpperCase(in.next().charAt(0)))
			System.out.println('A');
		else
			System.out.println('a'); Character.isUpperCase(in.next().charAt(0)) Character.isUpperCase Character in.next().charAt(0) in.next().charAt in.next() in.next in 0 System.out.println('A') System.out.println System.out System System.out '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 in=new Scanner(System.in);
		if(Character.isUpperCase(in.next().charAt(0)))
			System.out.println('A');
		else
			System.out.println('a');
	}
} public class Main{
	public static void main(String[] args) {
		Scanner in=new Scanner(System.in);
		if(Character.isUpperCase(in.next().charAt(0)))
			System.out.println('A');
		else
			System.out.println('a');
	}
} Main
import java.util.*;
public class Main{
	public static void main(String[] args) {
		Scanner in=new Scanner(System.in);
		if(Character.isUpperCase(in.next().charAt(0)))
			System.out.println('A');
		else
			System.out.println('a');
	}
}