import java.io.*;

class Main
{
    public static void main(String[] args) throws IOException
    {
        BufferedReader alpha = 
         new BufferedReader(new InputStreamReader(System.in));
        
        String a = alpha.readLine();

        if(a == a.toUpperCase()){
            System.out.print("A");
        } else if(a == a.toLowerCase()){
            System.out.print("a");
        }
    }
} import java.io.*; io.* java class Main
{
    public static void main(String[] args) throws IOException
    {
        BufferedReader alpha = 
         new BufferedReader(new InputStreamReader(System.in));
        
        String a = alpha.readLine();

        if(a == a.toUpperCase()){
            System.out.print("A");
        } else if(a == a.toLowerCase()){
            System.out.print("a");
        }
    }
} Main public static void main(String[] args) throws IOException
    {
        BufferedReader alpha = 
         new BufferedReader(new InputStreamReader(System.in));
        
        String a = alpha.readLine();

        if(a == a.toUpperCase()){
            System.out.print("A");
        } else if(a == a.toLowerCase()){
            System.out.print("a");
        }
    } main {
        BufferedReader alpha = 
         new BufferedReader(new InputStreamReader(System.in));
        
        String a = alpha.readLine();

        if(a == a.toUpperCase()){
            System.out.print("A");
        } else if(a == a.toLowerCase()){
            System.out.print("a");
        }
    } BufferedReader alpha = 
         new BufferedReader(new InputStreamReader(System.in)); alpha new BufferedReader(new InputStreamReader(System.in)) String a = alpha.readLine(); a alpha.readLine() alpha.readLine alpha if(a == a.toUpperCase()){
            System.out.print("A");
        } else if(a == a.toLowerCase()){
            System.out.print("a");
        } a == a.toUpperCase() a a.toUpperCase() a.toUpperCase a {
            System.out.print("A");
        } System.out.print("A") System.out.print System.out System System.out "A" if(a == a.toLowerCase()){
            System.out.print("a");
        } a == a.toLowerCase() a a.toLowerCase() a.toLowerCase a {
            System.out.print("a");
        } System.out.print("a") System.out.print System.out System System.out "a" String[] args args
import java.io.*;

class Main
{
    public static void main(String[] args) throws IOException
    {
        BufferedReader alpha = 
         new BufferedReader(new InputStreamReader(System.in));
        
        String a = alpha.readLine();

        if(a == a.toUpperCase()){
            System.out.print("A");
        } else if(a == a.toLowerCase()){
            System.out.print("a");
        }
    }
}