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