import java.util.Scanner;
class Main{
    public static void main(String []args){
          Scanner input=new Scanner(System.in);
      String temp=input.next();
      if(temp.toLowerCase().equals(temp)){
        System.out.print("a");
      }else{
        System.out.print("A");
      }
    }
} import java.util.Scanner; Scanner java.util class Main{
    public static void main(String []args){
          Scanner input=new Scanner(System.in);
      String temp=input.next();
      if(temp.toLowerCase().equals(temp)){
        System.out.print("a");
      }else{
        System.out.print("A");
      }
    }
} Main public static void main(String []args){
          Scanner input=new Scanner(System.in);
      String temp=input.next();
      if(temp.toLowerCase().equals(temp)){
        System.out.print("a");
      }else{
        System.out.print("A");
      }
    } main {
          Scanner input=new Scanner(System.in);
      String temp=input.next();
      if(temp.toLowerCase().equals(temp)){
        System.out.print("a");
      }else{
        System.out.print("A");
      }
    } Scanner input=new Scanner(System.in); input new Scanner(System.in) String temp=input.next(); temp input.next() input.next input if(temp.toLowerCase().equals(temp)){
        System.out.print("a");
      }else{
        System.out.print("A");
      } temp.toLowerCase().equals(temp) temp.toLowerCase().equals temp.toLowerCase() temp.toLowerCase temp temp {
        System.out.print("a");
      } System.out.print("a") System.out.print System.out System System.out "a" {
        System.out.print("A");
      } System.out.print("A") System.out.print System.out System System.out "A" String []args args
import java.util.Scanner;
class Main{
    public static void main(String []args){
          Scanner input=new Scanner(System.in);
      String temp=input.next();
      if(temp.toLowerCase().equals(temp)){
        System.out.print("a");
      }else{
        System.out.print("A");
      }
    }
}