import java.util.*;
public class Main {
	public static void main(String[] args){
		Scanner sc = new Scanner(System.in);
		// 文字の入力
		char c = sc.next().charAt(0);;
		// 出力
      	int ascii;
      	ascii = (int)c;

        if(ascii>=65 && 90>=ascii) 
          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);
		// 文字の入力
		char c = sc.next().charAt(0);;
		// 出力
      	int ascii;
      	ascii = (int)c;

        if(ascii>=65 && 90>=ascii) 
          System.out.println("A");
      	else 
          System.out.println("a");
	}
} Main public static void main(String[] args){
		Scanner sc = new Scanner(System.in);
		// 文字の入力
		char c = sc.next().charAt(0);;
		// 出力
      	int ascii;
      	ascii = (int)c;

        if(ascii>=65 && 90>=ascii) 
          System.out.println("A");
      	else 
          System.out.println("a");
	} main {
		Scanner sc = new Scanner(System.in);
		// 文字の入力
		char c = sc.next().charAt(0);;
		// 出力
      	int ascii;
      	ascii = (int)c;

        if(ascii>=65 && 90>=ascii) 
          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 int ascii; ascii ascii = (int)c ascii (int)c if(ascii>=65 && 90>=ascii) 
          System.out.println("A");
      	else 
          System.out.println("a"); ascii>=65 && 90>=ascii ascii>=65 ascii 65 90>=ascii 90 ascii System.out.println("A") System.out.println System.out System System.out "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);
		// 文字の入力
		char c = sc.next().charAt(0);;
		// 出力
      	int ascii;
      	ascii = (int)c;

        if(ascii>=65 && 90>=ascii) 
          System.out.println("A");
      	else 
          System.out.println("a");
	}
} public class Main {
	public static void main(String[] args){
		Scanner sc = new Scanner(System.in);
		// 文字の入力
		char c = sc.next().charAt(0);;
		// 出力
      	int ascii;
      	ascii = (int)c;

        if(ascii>=65 && 90>=ascii) 
          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);
		// 文字の入力
		char c = sc.next().charAt(0);;
		// 出力
      	int ascii;
      	ascii = (int)c;

        if(ascii>=65 && 90>=ascii) 
          System.out.println("A");
      	else 
          System.out.println("a");
	}
}