import java.util.ArrayList;
import java.util.Iterator;
import java.util.List;
import java.util.Scanner;
import java.util.TreeMap;

public class Main {
    public static void main(String[] args) {
        Scanner sc = new Scanner(System.in);
        String alpha = sc.next();
        String A=alpha.toUpperCase();
        
        if (A.equals(alpha)) {
            System.out.println("A");
        }else{
            System.out.println("a");
        }
        sc.close();
    }
} import java.util.ArrayList; ArrayList java.util import java.util.Iterator; Iterator java.util import java.util.List; List java.util import java.util.Scanner; Scanner java.util import java.util.TreeMap; TreeMap java.util public class Main {
    public static void main(String[] args) {
        Scanner sc = new Scanner(System.in);
        String alpha = sc.next();
        String A=alpha.toUpperCase();
        
        if (A.equals(alpha)) {
            System.out.println("A");
        }else{
            System.out.println("a");
        }
        sc.close();
    }
} Main public static void main(String[] args) {
        Scanner sc = new Scanner(System.in);
        String alpha = sc.next();
        String A=alpha.toUpperCase();
        
        if (A.equals(alpha)) {
            System.out.println("A");
        }else{
            System.out.println("a");
        }
        sc.close();
    } main {
        Scanner sc = new Scanner(System.in);
        String alpha = sc.next();
        String A=alpha.toUpperCase();
        
        if (A.equals(alpha)) {
            System.out.println("A");
        }else{
            System.out.println("a");
        }
        sc.close();
    } Scanner sc = new Scanner(System.in); sc new Scanner(System.in) String alpha = sc.next(); alpha sc.next() sc.next sc String A=alpha.toUpperCase(); A alpha.toUpperCase() alpha.toUpperCase alpha if (A.equals(alpha)) {
            System.out.println("A");
        }else{
            System.out.println("a");
        } A.equals(alpha) A.equals A alpha {
            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" sc.close() sc.close sc String[] args args public class Main {
    public static void main(String[] args) {
        Scanner sc = new Scanner(System.in);
        String alpha = sc.next();
        String A=alpha.toUpperCase();
        
        if (A.equals(alpha)) {
            System.out.println("A");
        }else{
            System.out.println("a");
        }
        sc.close();
    }
} public class Main {
    public static void main(String[] args) {
        Scanner sc = new Scanner(System.in);
        String alpha = sc.next();
        String A=alpha.toUpperCase();
        
        if (A.equals(alpha)) {
            System.out.println("A");
        }else{
            System.out.println("a");
        }
        sc.close();
    }
} Main
import java.util.ArrayList;
import java.util.Iterator;
import java.util.List;
import java.util.Scanner;
import java.util.TreeMap;

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