import java.util.*;

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

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