import java.util.*;

public class Main {
  public static void main(String[] args) {
    Scanner sc = new Scanner(System.in);
    String s = sc.next();
    String ans = "a";
    if(Character.isUpperCase(s.charAt(0))) ans = "A";
    System.out.println(ans);
  }
} import java.util.*; util.* java public class Main {
  public static void main(String[] args) {
    Scanner sc = new Scanner(System.in);
    String s = sc.next();
    String ans = "a";
    if(Character.isUpperCase(s.charAt(0))) ans = "A";
    System.out.println(ans);
  }
} Main public static void main(String[] args) {
    Scanner sc = new Scanner(System.in);
    String s = sc.next();
    String ans = "a";
    if(Character.isUpperCase(s.charAt(0))) ans = "A";
    System.out.println(ans);
  } main {
    Scanner sc = new Scanner(System.in);
    String s = sc.next();
    String ans = "a";
    if(Character.isUpperCase(s.charAt(0))) ans = "A";
    System.out.println(ans);
  } Scanner sc = new Scanner(System.in); sc new Scanner(System.in) String s = sc.next(); s sc.next() sc.next sc String ans = "a"; ans "a" if(Character.isUpperCase(s.charAt(0))) ans = "A"; Character.isUpperCase(s.charAt(0)) Character.isUpperCase Character s.charAt(0) s.charAt s 0 ans = "A" ans "A" System.out.println(ans) System.out.println System.out System System.out ans String[] args args public class Main {
  public static void main(String[] args) {
    Scanner sc = new Scanner(System.in);
    String s = sc.next();
    String ans = "a";
    if(Character.isUpperCase(s.charAt(0))) ans = "A";
    System.out.println(ans);
  }
} public class Main {
  public static void main(String[] args) {
    Scanner sc = new Scanner(System.in);
    String s = sc.next();
    String ans = "a";
    if(Character.isUpperCase(s.charAt(0))) ans = "A";
    System.out.println(ans);
  }
} Main
import java.util.*;

public class Main {
  public static void main(String[] args) {
    Scanner sc = new Scanner(System.in);
    String s = sc.next();
    String ans = "a";
    if(Character.isUpperCase(s.charAt(0))) ans = "A";
    System.out.println(ans);
  }
}