import 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') {
			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);
		if (c >= 'a') {
			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') {
			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') {
			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') {
			System.out.println('a');
		} else {
			System.out.println('A');
		} c >= 'a' c 'a' {
			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);
		if (c >= 'a') {
			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') {
			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);
		if (c >= 'a') {
			System.out.println('a');
		} else {
			System.out.println('A');
		}
	}
}