import java.util.*;
public class Main
{
  public static void main(String args[])
  {
    Scanner in=new Scanner(System.in);
    char c=in.next().charAt(0);
    char up=Character.toUpperCase(c);
    char down=Character.toLowerCase(c);
    if(c==up)
    {
      System.out.println("A");
    }
    else
    {
      System.out.println("a");
    }
  }
} import java.util.*; util.* java public class Main
{
  public static void main(String args[])
  {
    Scanner in=new Scanner(System.in);
    char c=in.next().charAt(0);
    char up=Character.toUpperCase(c);
    char down=Character.toLowerCase(c);
    if(c==up)
    {
      System.out.println("A");
    }
    else
    {
      System.out.println("a");
    }
  }
} Main public static void main(String args[])
  {
    Scanner in=new Scanner(System.in);
    char c=in.next().charAt(0);
    char up=Character.toUpperCase(c);
    char down=Character.toLowerCase(c);
    if(c==up)
    {
      System.out.println("A");
    }
    else
    {
      System.out.println("a");
    }
  } main {
    Scanner in=new Scanner(System.in);
    char c=in.next().charAt(0);
    char up=Character.toUpperCase(c);
    char down=Character.toLowerCase(c);
    if(c==up)
    {
      System.out.println("A");
    }
    else
    {
      System.out.println("a");
    }
  } Scanner in=new Scanner(System.in); in new Scanner(System.in) char c=in.next().charAt(0); c in.next().charAt(0) in.next().charAt in.next() in.next in 0 char up=Character.toUpperCase(c); up Character.toUpperCase(c) Character.toUpperCase Character c char down=Character.toLowerCase(c); down Character.toLowerCase(c) Character.toLowerCase Character c if(c==up)
    {
      System.out.println("A");
    }
    else
    {
      System.out.println("a");
    } c==up c up {
      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 in=new Scanner(System.in);
    char c=in.next().charAt(0);
    char up=Character.toUpperCase(c);
    char down=Character.toLowerCase(c);
    if(c==up)
    {
      System.out.println("A");
    }
    else
    {
      System.out.println("a");
    }
  }
} public class Main
{
  public static void main(String args[])
  {
    Scanner in=new Scanner(System.in);
    char c=in.next().charAt(0);
    char up=Character.toUpperCase(c);
    char down=Character.toLowerCase(c);
    if(c==up)
    {
      System.out.println("A");
    }
    else
    {
      System.out.println("a");
    }
  }
} Main
import java.util.*;
public class Main
{
  public static void main(String args[])
  {
    Scanner in=new Scanner(System.in);
    char c=in.next().charAt(0);
    char up=Character.toUpperCase(c);
    char down=Character.toLowerCase(c);
    if(c==up)
    {
      System.out.println("A");
    }
    else
    {
      System.out.println("a");
    }
  }
}