import java.util.*;


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