import java.io.*;
import java.util.*;

public class Main
{
	static Scanner scan = new Scanner(System.in);
	public static void solve() throws Exception
	{
		//BufferedReader in = new BufferedReader(new InputStreamReader(System.in));
		//StringTokenizer tk = new StringTokenizer(in.readLine());
		String s = scan.next();
	    if(Character.isUpperCase(s.charAt(0)))
	       System.out.println('A');
	    else
	       System.out.println('a');
	}
	public static void main(String[] args) throws Exception
	{
		if(scan.hasNext())
		{
			//int t= scan.nextInt();
			int t= 1;
			while(t-->0)
			{	
				solve();
			}
		}
	}
} import java.io.*; io.* java import java.util.*; util.* java public class Main
{
	static Scanner scan = new Scanner(System.in);
	public static void solve() throws Exception
	{
		//BufferedReader in = new BufferedReader(new InputStreamReader(System.in));
		//StringTokenizer tk = new StringTokenizer(in.readLine());
		String s = scan.next();
	    if(Character.isUpperCase(s.charAt(0)))
	       System.out.println('A');
	    else
	       System.out.println('a');
	}
	public static void main(String[] args) throws Exception
	{
		if(scan.hasNext())
		{
			//int t= scan.nextInt();
			int t= 1;
			while(t-->0)
			{	
				solve();
			}
		}
	}
} Main static Scanner scan = new Scanner(System.in); scan new Scanner(System.in) public static void solve() throws Exception
	{
		//BufferedReader in = new BufferedReader(new InputStreamReader(System.in));
		//StringTokenizer tk = new StringTokenizer(in.readLine());
		String s = scan.next();
	    if(Character.isUpperCase(s.charAt(0)))
	       System.out.println('A');
	    else
	       System.out.println('a');
	} solve {
		//BufferedReader in = new BufferedReader(new InputStreamReader(System.in));
		//StringTokenizer tk = new StringTokenizer(in.readLine());
		String s = scan.next();
	    if(Character.isUpperCase(s.charAt(0)))
	       System.out.println('A');
	    else
	       System.out.println('a');
	} String s = scan.next(); s scan.next() scan.next scan if(Character.isUpperCase(s.charAt(0)))
	       System.out.println('A');
	    else
	       System.out.println('a'); Character.isUpperCase(s.charAt(0)) Character.isUpperCase Character s.charAt(0) s.charAt s 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' public static void main(String[] args) throws Exception
	{
		if(scan.hasNext())
		{
			//int t= scan.nextInt();
			int t= 1;
			while(t-->0)
			{	
				solve();
			}
		}
	} main {
		if(scan.hasNext())
		{
			//int t= scan.nextInt();
			int t= 1;
			while(t-->0)
			{	
				solve();
			}
		}
	} if(scan.hasNext())
		{
			//int t= scan.nextInt();
			int t= 1;
			while(t-->0)
			{	
				solve();
			}
		} scan.hasNext() scan.hasNext scan {
			//int t= scan.nextInt();
			int t= 1;
			while(t-->0)
			{	
				solve();
			}
		} int t= 1; t 1 while(t-->0)
			{	
				solve();
			} t-->0 t-- t 0 {	
				solve();
			} solve() solve String[] args args public class Main
{
	static Scanner scan = new Scanner(System.in);
	public static void solve() throws Exception
	{
		//BufferedReader in = new BufferedReader(new InputStreamReader(System.in));
		//StringTokenizer tk = new StringTokenizer(in.readLine());
		String s = scan.next();
	    if(Character.isUpperCase(s.charAt(0)))
	       System.out.println('A');
	    else
	       System.out.println('a');
	}
	public static void main(String[] args) throws Exception
	{
		if(scan.hasNext())
		{
			//int t= scan.nextInt();
			int t= 1;
			while(t-->0)
			{	
				solve();
			}
		}
	}
} public class Main
{
	static Scanner scan = new Scanner(System.in);
	public static void solve() throws Exception
	{
		//BufferedReader in = new BufferedReader(new InputStreamReader(System.in));
		//StringTokenizer tk = new StringTokenizer(in.readLine());
		String s = scan.next();
	    if(Character.isUpperCase(s.charAt(0)))
	       System.out.println('A');
	    else
	       System.out.println('a');
	}
	public static void main(String[] args) throws Exception
	{
		if(scan.hasNext())
		{
			//int t= scan.nextInt();
			int t= 1;
			while(t-->0)
			{	
				solve();
			}
		}
	}
} Main
import java.io.*;
import java.util.*;

public class Main
{
	static Scanner scan = new Scanner(System.in);
	public static void solve() throws Exception
	{
		//BufferedReader in = new BufferedReader(new InputStreamReader(System.in));
		//StringTokenizer tk = new StringTokenizer(in.readLine());
		String s = scan.next();
	    if(Character.isUpperCase(s.charAt(0)))
	       System.out.println('A');
	    else
	       System.out.println('a');
	}
	public static void main(String[] args) throws Exception
	{
		if(scan.hasNext())
		{
			//int t= scan.nextInt();
			int t= 1;
			while(t-->0)
			{	
				solve();
			}
		}
	}
}