import java.util.Scanner;

class Main {
    public static void main(String[] args){
        Scanner stdIn = new Scanner(System.in);

        String a = stdIn.next();

        //文字列を小文字に
        if(a.toLowerCase() == a){
            System.out.println("a");
        }else {
            System.out.println("A");
        }
    } 
} import java.util.Scanner; Scanner java.util class Main {
    public static void main(String[] args){
        Scanner stdIn = new Scanner(System.in);

        String a = stdIn.next();

        //文字列を小文字に
        if(a.toLowerCase() == a){
            System.out.println("a");
        }else {
            System.out.println("A");
        }
    } 
} Main public static void main(String[] args){
        Scanner stdIn = new Scanner(System.in);

        String a = stdIn.next();

        //文字列を小文字に
        if(a.toLowerCase() == a){
            System.out.println("a");
        }else {
            System.out.println("A");
        }
    } main {
        Scanner stdIn = new Scanner(System.in);

        String a = stdIn.next();

        //文字列を小文字に
        if(a.toLowerCase() == a){
            System.out.println("a");
        }else {
            System.out.println("A");
        }
    } Scanner stdIn = new Scanner(System.in); stdIn new Scanner(System.in) String a = stdIn.next(); a stdIn.next() stdIn.next stdIn if(a.toLowerCase() == a){
            System.out.println("a");
        }else {
            System.out.println("A");
        } a.toLowerCase() == a a.toLowerCase() a.toLowerCase a a {
            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
import java.util.Scanner;

class Main {
    public static void main(String[] args){
        Scanner stdIn = new Scanner(System.in);

        String a = stdIn.next();

        //文字列を小文字に
        if(a.toLowerCase() == a){
            System.out.println("a");
        }else {
            System.out.println("A");
        }
    } 
}