import java.util.*;

public class Main{
    public static void main(String[] args){
        Scanner sc = new Scanner(System.in);
        String str = sc.next();
        System.out.println(str.matches("[A-Z]") ? "A" : "a");
    }
} import java.util.*; util.* java public class Main{
    public static void main(String[] args){
        Scanner sc = new Scanner(System.in);
        String str = sc.next();
        System.out.println(str.matches("[A-Z]") ? "A" : "a");
    }
} Main public static void main(String[] args){
        Scanner sc = new Scanner(System.in);
        String str = sc.next();
        System.out.println(str.matches("[A-Z]") ? "A" : "a");
    } main {
        Scanner sc = new Scanner(System.in);
        String str = sc.next();
        System.out.println(str.matches("[A-Z]") ? "A" : "a");
    } Scanner sc = new Scanner(System.in); sc new Scanner(System.in) String str = sc.next(); str sc.next() sc.next sc System.out.println(str.matches("[A-Z]") ? "A" : "a") System.out.println System.out System System.out str.matches("[A-Z]") ? "A" : "a" str.matches("[A-Z]") str.matches str "[A-Z]" "A" "a" String[] args args public class Main{
    public static void main(String[] args){
        Scanner sc = new Scanner(System.in);
        String str = sc.next();
        System.out.println(str.matches("[A-Z]") ? "A" : "a");
    }
} public class Main{
    public static void main(String[] args){
        Scanner sc = new Scanner(System.in);
        String str = sc.next();
        System.out.println(str.matches("[A-Z]") ? "A" : "a");
    }
} Main
import java.util.*;

public class Main{
    public static void main(String[] args){
        Scanner sc = new Scanner(System.in);
        String str = sc.next();
        System.out.println(str.matches("[A-Z]") ? "A" : "a");
    }
}