import java.util.*;

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

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

        if((int)n >= 97){
            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 n = sc.next().charAt(0);

        if((int)n >= 97){
            System.out.println("a");
        }else{
            System.out.println("A");
        }

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

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

        if((int)n >= 97){
            System.out.println("a");
        }else{
            System.out.println("A");
        }

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

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

        if((int)n >= 97){
            System.out.println("a");
        }else{
            System.out.println("A");
        }

    } Scanner sc = new Scanner(System.in); sc new Scanner(System.in) char n = sc.next().charAt(0); n sc.next().charAt(0) sc.next().charAt sc.next() sc.next sc 0 if((int)n >= 97){
            System.out.println("a");
        }else{
            System.out.println("A");
        } (int)n >= 97 (int)n 97 {
            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 n = sc.next().charAt(0);

        if((int)n >= 97){
            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 n = sc.next().charAt(0);

        if((int)n >= 97){
            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 n = sc.next().charAt(0);

        if((int)n >= 97){
            System.out.println("a");
        }else{
            System.out.println("A");
        }

    }
}
