import java.util.Scanner;

public class Main {

	public static void main(String[] args) {
		// TODO Auto-generated method stub
		try (Scanner sc = new Scanner(System.in)) {
			char[] n = sc.next().toCharArray();
			String ans = "a";

			if (Character.isUpperCase(n[0])) {

				ans = "A";
			}
			System.out.println(ans);


		} catch (Exception e) {
			// TODO: handle exception
		}
	}
} import java.util.Scanner; Scanner java.util public class Main {

	public static void main(String[] args) {
		// TODO Auto-generated method stub
		try (Scanner sc = new Scanner(System.in)) {
			char[] n = sc.next().toCharArray();
			String ans = "a";

			if (Character.isUpperCase(n[0])) {

				ans = "A";
			}
			System.out.println(ans);


		} catch (Exception e) {
			// TODO: handle exception
		}
	}
} Main public static void main(String[] args) {
		// TODO Auto-generated method stub
		try (Scanner sc = new Scanner(System.in)) {
			char[] n = sc.next().toCharArray();
			String ans = "a";

			if (Character.isUpperCase(n[0])) {

				ans = "A";
			}
			System.out.println(ans);


		} catch (Exception e) {
			// TODO: handle exception
		}
	} main {
		// TODO Auto-generated method stub
		try (Scanner sc = new Scanner(System.in)) {
			char[] n = sc.next().toCharArray();
			String ans = "a";

			if (Character.isUpperCase(n[0])) {

				ans = "A";
			}
			System.out.println(ans);


		} catch (Exception e) {
			// TODO: handle exception
		}
	} try (Scanner sc = new Scanner(System.in)) {
			char[] n = sc.next().toCharArray();
			String ans = "a";

			if (Character.isUpperCase(n[0])) {

				ans = "A";
			}
			System.out.println(ans);


		} catch (Exception e) {
			// TODO: handle exception
		} catch (Exception e) {
			// TODO: handle exception
		} Exception e {
			// TODO: handle exception
		} {
			char[] n = sc.next().toCharArray();
			String ans = "a";

			if (Character.isUpperCase(n[0])) {

				ans = "A";
			}
			System.out.println(ans);


		} Scanner sc = new Scanner(System.in) Scanner sc = new Scanner(System.in) new Scanner(System.in) char[] n = sc.next().toCharArray(); n sc.next().toCharArray() sc.next().toCharArray sc.next() sc.next sc String ans = "a"; ans "a" if (Character.isUpperCase(n[0])) {

				ans = "A";
			} Character.isUpperCase(n[0]) Character.isUpperCase Character n[0] n 0 {

				ans = "A";
			} ans = "A" ans "A" System.out.println(ans) System.out.println System.out System System.out ans String[] args args public class Main {

	public static void main(String[] args) {
		// TODO Auto-generated method stub
		try (Scanner sc = new Scanner(System.in)) {
			char[] n = sc.next().toCharArray();
			String ans = "a";

			if (Character.isUpperCase(n[0])) {

				ans = "A";
			}
			System.out.println(ans);


		} catch (Exception e) {
			// TODO: handle exception
		}
	}
} public class Main {

	public static void main(String[] args) {
		// TODO Auto-generated method stub
		try (Scanner sc = new Scanner(System.in)) {
			char[] n = sc.next().toCharArray();
			String ans = "a";

			if (Character.isUpperCase(n[0])) {

				ans = "A";
			}
			System.out.println(ans);


		} catch (Exception e) {
			// TODO: handle exception
		}
	}
} Main
import java.util.Scanner;

public class Main {

	public static void main(String[] args) {
		// TODO Auto-generated method stub
		try (Scanner sc = new Scanner(System.in)) {
			char[] n = sc.next().toCharArray();
			String ans = "a";

			if (Character.isUpperCase(n[0])) {

				ans = "A";
			}
			System.out.println(ans);


		} catch (Exception e) {
			// TODO: handle exception
		}
	}
}
