import java.util.Scanner;

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