import java.util.*;

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

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