import java.util.*;

public class Main {

    public static void main(String[] args) {
        Scanner sc = new Scanner(System.in);
        String a = sc.next();
        sc.close();

        char s = a.toCharArray()[0];

        String res = "";
        if (Character.isLowerCase(s)) {
            res = "a";
        } else {
            res = "A";
        }

        System.out.println(res);

    }
} import java.util.*; util.* java public class Main {

    public static void main(String[] args) {
        Scanner sc = new Scanner(System.in);
        String a = sc.next();
        sc.close();

        char s = a.toCharArray()[0];

        String res = "";
        if (Character.isLowerCase(s)) {
            res = "a";
        } else {
            res = "A";
        }

        System.out.println(res);

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

        char s = a.toCharArray()[0];

        String res = "";
        if (Character.isLowerCase(s)) {
            res = "a";
        } else {
            res = "A";
        }

        System.out.println(res);

    } main {
        Scanner sc = new Scanner(System.in);
        String a = sc.next();
        sc.close();

        char s = a.toCharArray()[0];

        String res = "";
        if (Character.isLowerCase(s)) {
            res = "a";
        } else {
            res = "A";
        }

        System.out.println(res);

    } Scanner sc = new Scanner(System.in); sc new Scanner(System.in) String a = sc.next(); a sc.next() sc.next sc sc.close() sc.close sc char s = a.toCharArray()[0]; s a.toCharArray()[0] a.toCharArray() a.toCharArray a 0 String res = ""; res "" if (Character.isLowerCase(s)) {
            res = "a";
        } else {
            res = "A";
        } Character.isLowerCase(s) Character.isLowerCase Character s {
            res = "a";
        } res = "a" res "a" {
            res = "A";
        } res = "A" res "A" System.out.println(res) System.out.println System.out System System.out res String[] args args public class Main {

    public static void main(String[] args) {
        Scanner sc = new Scanner(System.in);
        String a = sc.next();
        sc.close();

        char s = a.toCharArray()[0];

        String res = "";
        if (Character.isLowerCase(s)) {
            res = "a";
        } else {
            res = "A";
        }

        System.out.println(res);

    }
} public class Main {

    public static void main(String[] args) {
        Scanner sc = new Scanner(System.in);
        String a = sc.next();
        sc.close();

        char s = a.toCharArray()[0];

        String res = "";
        if (Character.isLowerCase(s)) {
            res = "a";
        } else {
            res = "A";
        }

        System.out.println(res);

    }
} Main
import java.util.*;

public class Main {

    public static void main(String[] args) {
        Scanner sc = new Scanner(System.in);
        String a = sc.next();
        sc.close();

        char s = a.toCharArray()[0];

        String res = "";
        if (Character.isLowerCase(s)) {
            res = "a";
        } else {
            res = "A";
        }

        System.out.println(res);

    }
}
