import java.util.*;

public class Main
{
	public static void main(String[] args)
	{
		Scanner sc=new Scanner(System.in);
		String str=sc.next();
		String bs=str.toUpperCase();
		String ss=str.toLowerCase();
		if(str.equals(bs))
		{
			System.out.println("A");
		}
		else if(str.equals(ss))
		{
			System.out.println("a");
		}
		sc.close();
	}
} import java.util.*; util.* java public class Main
{
	public static void main(String[] args)
	{
		Scanner sc=new Scanner(System.in);
		String str=sc.next();
		String bs=str.toUpperCase();
		String ss=str.toLowerCase();
		if(str.equals(bs))
		{
			System.out.println("A");
		}
		else if(str.equals(ss))
		{
			System.out.println("a");
		}
		sc.close();
	}
} Main public static void main(String[] args)
	{
		Scanner sc=new Scanner(System.in);
		String str=sc.next();
		String bs=str.toUpperCase();
		String ss=str.toLowerCase();
		if(str.equals(bs))
		{
			System.out.println("A");
		}
		else if(str.equals(ss))
		{
			System.out.println("a");
		}
		sc.close();
	} main {
		Scanner sc=new Scanner(System.in);
		String str=sc.next();
		String bs=str.toUpperCase();
		String ss=str.toLowerCase();
		if(str.equals(bs))
		{
			System.out.println("A");
		}
		else if(str.equals(ss))
		{
			System.out.println("a");
		}
		sc.close();
	} Scanner sc=new Scanner(System.in); sc new Scanner(System.in) String str=sc.next(); str sc.next() sc.next sc String bs=str.toUpperCase(); bs str.toUpperCase() str.toUpperCase str String ss=str.toLowerCase(); ss str.toLowerCase() str.toLowerCase str if(str.equals(bs))
		{
			System.out.println("A");
		}
		else if(str.equals(ss))
		{
			System.out.println("a");
		} str.equals(bs) str.equals str bs {
			System.out.println("A");
		} System.out.println("A") System.out.println System.out System System.out "A" if(str.equals(ss))
		{
			System.out.println("a");
		} str.equals(ss) str.equals str ss {
			System.out.println("a");
		} System.out.println("a") System.out.println System.out System System.out "a" sc.close() sc.close sc String[] args args public class Main
{
	public static void main(String[] args)
	{
		Scanner sc=new Scanner(System.in);
		String str=sc.next();
		String bs=str.toUpperCase();
		String ss=str.toLowerCase();
		if(str.equals(bs))
		{
			System.out.println("A");
		}
		else if(str.equals(ss))
		{
			System.out.println("a");
		}
		sc.close();
	}
} public class Main
{
	public static void main(String[] args)
	{
		Scanner sc=new Scanner(System.in);
		String str=sc.next();
		String bs=str.toUpperCase();
		String ss=str.toLowerCase();
		if(str.equals(bs))
		{
			System.out.println("A");
		}
		else if(str.equals(ss))
		{
			System.out.println("a");
		}
		sc.close();
	}
} Main
import java.util.*;

public class Main
{
	public static void main(String[] args)
	{
		Scanner sc=new Scanner(System.in);
		String str=sc.next();
		String bs=str.toUpperCase();
		String ss=str.toLowerCase();
		if(str.equals(bs))
		{
			System.out.println("A");
		}
		else if(str.equals(ss))
		{
			System.out.println("a");
		}
		sc.close();
	}
}
