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

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

  } main {
    Scanner stdIn = new Scanner(System.in);
    String a = stdIn.next();
  
    if(Character.isUpperCase(a.charAt(0))){
      System.out.println("A");
    			}
      else
        System.out.println("a");

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

  }
}