import java.util.*;

public class Main {
    public static void main(String[] args) {
        Scanner sc = new Scanner(System.in);

        char alpha = sc.next().charAt(0);

        if ('A' <= alpha && alpha <= 'Z') 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 alpha = sc.next().charAt(0);

        if ('A' <= alpha && alpha <= 'Z') System.out.println("A");
        else System.out.println("a");

    }

} Main public static void main(String[] args) {
        Scanner sc = new Scanner(System.in);

        char alpha = sc.next().charAt(0);

        if ('A' <= alpha && alpha <= 'Z') System.out.println("A");
        else System.out.println("a");

    } main {
        Scanner sc = new Scanner(System.in);

        char alpha = sc.next().charAt(0);

        if ('A' <= alpha && alpha <= 'Z') System.out.println("A");
        else System.out.println("a");

    } Scanner sc = new Scanner(System.in); sc new Scanner(System.in) char alpha = sc.next().charAt(0); alpha sc.next().charAt(0) sc.next().charAt sc.next() sc.next sc 0 if ('A' <= alpha && alpha <= 'Z') System.out.println("A");
        else System.out.println("a"); 'A' <= alpha && alpha <= 'Z' 'A' <= alpha 'A' alpha alpha <= 'Z' alpha 'Z' System.out.println("A") System.out.println System.out System System.out "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 alpha = sc.next().charAt(0);

        if ('A' <= alpha && alpha <= 'Z') 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 alpha = sc.next().charAt(0);

        if ('A' <= alpha && alpha <= 'Z') 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 alpha = sc.next().charAt(0);

        if ('A' <= alpha && alpha <= 'Z') System.out.println("A");
        else System.out.println("a");

    }

}