import java.util.Scanner;

public class Main {
    public static void main(String[] args) {
        Scanner in = new Scanner(System.in);
        int a = 0;
        int r=(int)'a';
        char taher = in.next().charAt(0);
        if ((int)taher>=r)
        System.out.print('a');
        else {
            System.out.print('A');
        }
    }
} import java.util.Scanner; Scanner java.util public class Main {
    public static void main(String[] args) {
        Scanner in = new Scanner(System.in);
        int a = 0;
        int r=(int)'a';
        char taher = in.next().charAt(0);
        if ((int)taher>=r)
        System.out.print('a');
        else {
            System.out.print('A');
        }
    }
} Main public static void main(String[] args) {
        Scanner in = new Scanner(System.in);
        int a = 0;
        int r=(int)'a';
        char taher = in.next().charAt(0);
        if ((int)taher>=r)
        System.out.print('a');
        else {
            System.out.print('A');
        }
    } main {
        Scanner in = new Scanner(System.in);
        int a = 0;
        int r=(int)'a';
        char taher = in.next().charAt(0);
        if ((int)taher>=r)
        System.out.print('a');
        else {
            System.out.print('A');
        }
    } Scanner in = new Scanner(System.in); in new Scanner(System.in) int a = 0; a 0 int r=(int)'a'; r (int)'a' char taher = in.next().charAt(0); taher in.next().charAt(0) in.next().charAt in.next() in.next in 0 if ((int)taher>=r)
        System.out.print('a');
        else {
            System.out.print('A');
        } (int)taher>=r (int)taher r 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 in = new Scanner(System.in);
        int a = 0;
        int r=(int)'a';
        char taher = in.next().charAt(0);
        if ((int)taher>=r)
        System.out.print('a');
        else {
            System.out.print('A');
        }
    }
} public class Main {
    public static void main(String[] args) {
        Scanner in = new Scanner(System.in);
        int a = 0;
        int r=(int)'a';
        char taher = in.next().charAt(0);
        if ((int)taher>=r)
        System.out.print('a');
        else {
            System.out.print('A');
        }
    }
} Main
import java.util.Scanner;

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