import java.util.Scanner;

class Main{
  public static void main(String []a){
    Scanner sc=new Scanner(System.in);
    char ch=sc.next().charAt(0);
    
    if(ch>90){
      System.out.println("a");
    }
    else{
      System.out.println("A");
    }
  }
} import java.util.Scanner; Scanner java.util class Main{
  public static void main(String []a){
    Scanner sc=new Scanner(System.in);
    char ch=sc.next().charAt(0);
    
    if(ch>90){
      System.out.println("a");
    }
    else{
      System.out.println("A");
    }
  }
} Main public static void main(String []a){
    Scanner sc=new Scanner(System.in);
    char ch=sc.next().charAt(0);
    
    if(ch>90){
      System.out.println("a");
    }
    else{
      System.out.println("A");
    }
  } main {
    Scanner sc=new Scanner(System.in);
    char ch=sc.next().charAt(0);
    
    if(ch>90){
      System.out.println("a");
    }
    else{
      System.out.println("A");
    }
  } Scanner sc=new Scanner(System.in); sc new Scanner(System.in) char ch=sc.next().charAt(0); ch sc.next().charAt(0) sc.next().charAt sc.next() sc.next sc 0 if(ch>90){
      System.out.println("a");
    }
    else{
      System.out.println("A");
    } ch>90 ch 90 {
      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 []a a
import java.util.Scanner;

class Main{
  public static void main(String []a){
    Scanner sc=new Scanner(System.in);
    char ch=sc.next().charAt(0);
    
    if(ch>90){
      System.out.println("a");
    }
    else{
      System.out.println("A");
    }
  }
}