import java.util.*;

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