import java.util.*;
public class Main {
  public static void main (String[] args) {
    Scanner sc = new Scanner(System.in);
    String S = sc.next();
    String ans;
    ans = (S.toLowerCase().equals(S))? "a" : "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;
    ans = (S.toLowerCase().equals(S))? "a" : "A";
    System.out.println(ans);
  }
} Main public static void main (String[] args) {
    Scanner sc = new Scanner(System.in);
    String S = sc.next();
    String ans;
    ans = (S.toLowerCase().equals(S))? "a" : "A";
    System.out.println(ans);
  } main {
    Scanner sc = new Scanner(System.in);
    String S = sc.next();
    String ans;
    ans = (S.toLowerCase().equals(S))? "a" : "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; ans ans = (S.toLowerCase().equals(S))? "a" : "A" ans (S.toLowerCase().equals(S))? "a" : "A" (S.toLowerCase().equals(S)) S.toLowerCase().equals S.toLowerCase() S.toLowerCase S S "a" "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;
    ans = (S.toLowerCase().equals(S))? "a" : "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;
    ans = (S.toLowerCase().equals(S))? "a" : "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;
    ans = (S.toLowerCase().equals(S))? "a" : "A";
    System.out.println(ans);
  }
}