import java.util.*;


public class Main {
    public static void main(String[] args) {

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

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

        Scanner sc = new Scanner(System.in);
        char chr = sc.next().charAt(0);
        if (Character.isUpperCase(chr)) {
            System.out.println("A");
        } else {
            System.out.println("a");
        }
    } main {

        Scanner sc = new Scanner(System.in);
        char chr = sc.next().charAt(0);
        if (Character.isUpperCase(chr)) {
            System.out.println("A");
        } else {
            System.out.println("a");
        }
    } Scanner sc = new Scanner(System.in); sc new Scanner(System.in) char chr = sc.next().charAt(0); chr sc.next().charAt(0) sc.next().charAt sc.next() sc.next sc 0 if (Character.isUpperCase(chr)) {
            System.out.println("A");
        } else {
            System.out.println("a");
        } Character.isUpperCase(chr) Character.isUpperCase Character chr {
            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) {

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

        Scanner sc = new Scanner(System.in);
        char chr = sc.next().charAt(0);
        if (Character.isUpperCase(chr)) {
            System.out.println("A");
        } else {
            System.out.println("a");
        }
    }
} Main
import java.util.*;


public class Main {
    public static void main(String[] args) {

        Scanner sc = new Scanner(System.in);
        char chr = sc.next().charAt(0);
        if (Character.isUpperCase(chr)) {
            System.out.println("A");
        } else {
            System.out.println("a");
        }
    }
}