import java.util.Scanner;

public class Main {

	public static void main(String[] args) {
		Scanner scanner=new Scanner(System.in);
		String S=scanner.nextLine();
		String result="a";
		if(Character.isUpperCase(S.charAt(0))) {
			result="A";
		}
		System.out.println(result);
	}
} import java.util.Scanner; Scanner java.util public class Main {

	public static void main(String[] args) {
		Scanner scanner=new Scanner(System.in);
		String S=scanner.nextLine();
		String result="a";
		if(Character.isUpperCase(S.charAt(0))) {
			result="A";
		}
		System.out.println(result);
	}
} Main public static void main(String[] args) {
		Scanner scanner=new Scanner(System.in);
		String S=scanner.nextLine();
		String result="a";
		if(Character.isUpperCase(S.charAt(0))) {
			result="A";
		}
		System.out.println(result);
	} main {
		Scanner scanner=new Scanner(System.in);
		String S=scanner.nextLine();
		String result="a";
		if(Character.isUpperCase(S.charAt(0))) {
			result="A";
		}
		System.out.println(result);
	} Scanner scanner=new Scanner(System.in); scanner new Scanner(System.in) String S=scanner.nextLine(); S scanner.nextLine() scanner.nextLine scanner String result="a"; result "a" if(Character.isUpperCase(S.charAt(0))) {
			result="A";
		} Character.isUpperCase(S.charAt(0)) Character.isUpperCase Character S.charAt(0) S.charAt S 0 {
			result="A";
		} result="A" result "A" System.out.println(result) System.out.println System.out System System.out result String[] args args public class Main {

	public static void main(String[] args) {
		Scanner scanner=new Scanner(System.in);
		String S=scanner.nextLine();
		String result="a";
		if(Character.isUpperCase(S.charAt(0))) {
			result="A";
		}
		System.out.println(result);
	}
} public class Main {

	public static void main(String[] args) {
		Scanner scanner=new Scanner(System.in);
		String S=scanner.nextLine();
		String result="a";
		if(Character.isUpperCase(S.charAt(0))) {
			result="A";
		}
		System.out.println(result);
	}
} Main
import java.util.Scanner;

public class Main {

	public static void main(String[] args) {
		Scanner scanner=new Scanner(System.in);
		String S=scanner.nextLine();
		String result="a";
		if(Character.isUpperCase(S.charAt(0))) {
			result="A";
		}
		System.out.println(result);
	}
}