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