import java.util.Scanner;

public class Main {
    public static void main(String[] args) {
        Scanner sc = new Scanner(System.in);
        char c = sc.next().charAt(0);
        if (c-'a'>=0)System.out.println("a");
        else System.out.println("A");
    }
} import java.util.Scanner; Scanner java.util public class Main {
    public static void main(String[] args) {
        Scanner sc = new Scanner(System.in);
        char c = sc.next().charAt(0);
        if (c-'a'>=0)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);
        if (c-'a'>=0)System.out.println("a");
        else System.out.println("A");
    } main {
        Scanner sc = new Scanner(System.in);
        char c = sc.next().charAt(0);
        if (c-'a'>=0)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 if (c-'a'>=0)System.out.println("a");
        else System.out.println("A"); c-'a'>=0 c-'a' c 'a' 0 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 c = sc.next().charAt(0);
        if (c-'a'>=0)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);
        if (c-'a'>=0)System.out.println("a");
        else System.out.println("A");
    }
} Main
import java.util.Scanner;

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