import java.util.*;
import java.io.*;
import java.lang.*;

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

        String a = sc.next();

        if (a.toUpperCase().equals(a))
            System.out.println("A");
        else
            System.out.println("a");
    }
} import java.util.*; util.* java import java.io.*; io.* java import java.lang.*; lang.* java public class Main {
    public static void main(String[] args){
        Scanner sc = new Scanner(System.in);

        String a = sc.next();

        if (a.toUpperCase().equals(a))
            System.out.println("A");
        else
            System.out.println("a");
    }
} Main public static void main(String[] args){
        Scanner sc = new Scanner(System.in);

        String a = sc.next();

        if (a.toUpperCase().equals(a))
            System.out.println("A");
        else
            System.out.println("a");
    } main {
        Scanner sc = new Scanner(System.in);

        String a = sc.next();

        if (a.toUpperCase().equals(a))
            System.out.println("A");
        else
            System.out.println("a");
    } Scanner sc = new Scanner(System.in); sc new Scanner(System.in) String a = sc.next(); a sc.next() sc.next sc if (a.toUpperCase().equals(a))
            System.out.println("A");
        else
            System.out.println("a"); a.toUpperCase().equals(a) a.toUpperCase().equals a.toUpperCase() a.toUpperCase a a 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);

        String a = sc.next();

        if (a.toUpperCase().equals(a))
            System.out.println("A");
        else
            System.out.println("a");
    }
} public class Main {
    public static void main(String[] args){
        Scanner sc = new Scanner(System.in);

        String a = sc.next();

        if (a.toUpperCase().equals(a))
            System.out.println("A");
        else
            System.out.println("a");
    }
} Main
import java.util.*;
import java.io.*;
import java.lang.*;

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

        String a = sc.next();

        if (a.toUpperCase().equals(a))
            System.out.println("A");
        else
            System.out.println("a");
    }
}
