import java.util.*;

public class Main{
    public static void main(String[] args){
        Scanner sc = new Scanner(System.in);
        String s = sc.next();
        char a = s.charAt(0);

        if ( Character.isUpperCase(a)) {
            System.out.print('A');
        } else {
            System.out.print('a');
        }
    }

} import java.util.*; util.* java public class Main{
    public static void main(String[] args){
        Scanner sc = new Scanner(System.in);
        String s = sc.next();
        char a = s.charAt(0);

        if ( Character.isUpperCase(a)) {
            System.out.print('A');
        } else {
            System.out.print('a');
        }
    }

} Main public static void main(String[] args){
        Scanner sc = new Scanner(System.in);
        String s = sc.next();
        char a = s.charAt(0);

        if ( Character.isUpperCase(a)) {
            System.out.print('A');
        } else {
            System.out.print('a');
        }
    } main {
        Scanner sc = new Scanner(System.in);
        String s = sc.next();
        char a = s.charAt(0);

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

        if ( Character.isUpperCase(a)) {
            System.out.print('A');
        } else {
            System.out.print('a');
        }
    }

} public class Main{
    public static void main(String[] args){
        Scanner sc = new Scanner(System.in);
        String s = sc.next();
        char a = s.charAt(0);

        if ( Character.isUpperCase(a)) {
            System.out.print('A');
        } else {
            System.out.print('a');
        }
    }

} Main
import java.util.*;

public class Main{
    public static void main(String[] args){
        Scanner sc = new Scanner(System.in);
        String s = sc.next();
        char a = s.charAt(0);

        if ( Character.isUpperCase(a)) {
            System.out.print('A');
        } else {
            System.out.print('a');
        }
    }

}