import java.util.Scanner;
import java.lang.Character;

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

public class Main {
    public static void main(String[] args) throws Exception {
        Scanner sc = new Scanner(System.in);
        String a = sc.next();
        if(Character.isUpperCase(a.charAt(0))){
            System.out.print("A");
        }else{
            System.out.print("a");
        }
    }
}
