import java.util.Scanner;

public class Main {
	static int intN =0;
	static int sosuCnt =0;

	public static void main(String[] args) {
		//test
		Scanner sc = new Scanner(System.in);
		String s = sc.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 {
	static int intN =0;
	static int sosuCnt =0;

	public static void main(String[] args) {
		//test
		Scanner sc = new Scanner(System.in);
		String s = sc.nextLine();
		String result = "a";
		if (Character.isUpperCase( s.charAt( 0 ) )) {
			result = "A";
		}

		System.out.println(result);
	}

} Main static int intN =0; intN 0 static int sosuCnt =0; sosuCnt 0 public static void main(String[] args) {
		//test
		Scanner sc = new Scanner(System.in);
		String s = sc.nextLine();
		String result = "a";
		if (Character.isUpperCase( s.charAt( 0 ) )) {
			result = "A";
		}

		System.out.println(result);
	} main {
		//test
		Scanner sc = new Scanner(System.in);
		String s = sc.nextLine();
		String result = "a";
		if (Character.isUpperCase( s.charAt( 0 ) )) {
			result = "A";
		}

		System.out.println(result);
	} Scanner sc = new Scanner(System.in); sc new Scanner(System.in) String s = sc.nextLine(); s sc.nextLine() sc.nextLine sc 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 {
	static int intN =0;
	static int sosuCnt =0;

	public static void main(String[] args) {
		//test
		Scanner sc = new Scanner(System.in);
		String s = sc.nextLine();
		String result = "a";
		if (Character.isUpperCase( s.charAt( 0 ) )) {
			result = "A";
		}

		System.out.println(result);
	}

} public class Main {
	static int intN =0;
	static int sosuCnt =0;

	public static void main(String[] args) {
		//test
		Scanner sc = new Scanner(System.in);
		String s = sc.nextLine();
		String result = "a";
		if (Character.isUpperCase( s.charAt( 0 ) )) {
			result = "A";
		}

		System.out.println(result);
	}

} Main
import java.util.Scanner;

public class Main {
	static int intN =0;
	static int sosuCnt =0;

	public static void main(String[] args) {
		//test
		Scanner sc = new Scanner(System.in);
		String s = sc.nextLine();
		String result = "a";
		if (Character.isUpperCase( s.charAt( 0 ) )) {
			result = "A";
		}

		System.out.println(result);
	}

}
