import java.util.*;
public class Main {
	public static void main(String[] args){
		Scanner sc=new Scanner(System.in);
		String s = sc.nextLine();
		if((s.charAt(0)-0)>=97){
			System.out.println("a");
		}else{
			System.out.println('A');
		}
	}
} import java.util.*; util.* java public class Main {
	public static void main(String[] args){
		Scanner sc=new Scanner(System.in);
		String s = sc.nextLine();
		if((s.charAt(0)-0)>=97){
			System.out.println("a");
		}else{
			System.out.println('A');
		}
	}
} Main public static void main(String[] args){
		Scanner sc=new Scanner(System.in);
		String s = sc.nextLine();
		if((s.charAt(0)-0)>=97){
			System.out.println("a");
		}else{
			System.out.println('A');
		}
	} main {
		Scanner sc=new Scanner(System.in);
		String s = sc.nextLine();
		if((s.charAt(0)-0)>=97){
			System.out.println("a");
		}else{
			System.out.println('A');
		}
	} Scanner sc=new Scanner(System.in); sc new Scanner(System.in) String s = sc.nextLine(); s sc.nextLine() sc.nextLine sc if((s.charAt(0)-0)>=97){
			System.out.println("a");
		}else{
			System.out.println('A');
		} (s.charAt(0)-0)>=97 (s.charAt(0)-0) s.charAt(0) s.charAt s 0 0 97 {
			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);
		String s = sc.nextLine();
		if((s.charAt(0)-0)>=97){
			System.out.println("a");
		}else{
			System.out.println('A');
		}
	}
} public class Main {
	public static void main(String[] args){
		Scanner sc=new Scanner(System.in);
		String s = sc.nextLine();
		if((s.charAt(0)-0)>=97){
			System.out.println("a");
		}else{
			System.out.println('A');
		}
	}
} Main
import java.util.*;
public class Main {
	public static void main(String[] args){
		Scanner sc=new Scanner(System.in);
		String s = sc.nextLine();
		if((s.charAt(0)-0)>=97){
			System.out.println("a");
		}else{
			System.out.println('A');
		}
	}
}
