import java.util.*;
import java.util.ArrayList;
import java.util.Collections;
import java.util.HashMap;
import java.util.TreeMap;
import java.util.ArrayDeque;
import java.awt.Point;
 
class Main{
    public static void main(String[] args){
        
        Scanner sc = new Scanner(System.in);
        
        String a = sc.next();
        String A = a.toUpperCase();

        if(a.equals(A)){
            System.out.println("A");
        }
        else{
            System.out.println("a");
        }
    } 
} import java.util.*; util.* java import java.util.ArrayList; ArrayList java.util import java.util.Collections; Collections java.util import java.util.HashMap; HashMap java.util import java.util.TreeMap; TreeMap java.util import java.util.ArrayDeque; ArrayDeque java.util import java.awt.Point; Point java.awt class Main{
    public static void main(String[] args){
        
        Scanner sc = new Scanner(System.in);
        
        String a = sc.next();
        String A = a.toUpperCase();

        if(a.equals(A)){
            System.out.println("A");
        }
        else{
            System.out.println("a");
        }
    } 
} Main public static void main(String[] args){
        
        Scanner sc = new Scanner(System.in);
        
        String a = sc.next();
        String A = a.toUpperCase();

        if(a.equals(A)){
            System.out.println("A");
        }
        else{
            System.out.println("a");
        }
    } main {
        
        Scanner sc = new Scanner(System.in);
        
        String a = sc.next();
        String A = a.toUpperCase();

        if(a.equals(A)){
            System.out.println("A");
        }
        else{
            System.out.println("a");
        }
    } Scanner sc = new Scanner(System.in); sc new Scanner(System.in) String a = sc.next(); a sc.next() sc.next sc String A = a.toUpperCase(); A a.toUpperCase() a.toUpperCase a if(a.equals(A)){
            System.out.println("A");
        }
        else{
            System.out.println("a");
        } a.equals(A) a.equals a A {
            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
import java.util.*;
import java.util.ArrayList;
import java.util.Collections;
import java.util.HashMap;
import java.util.TreeMap;
import java.util.ArrayDeque;
import java.awt.Point;
 
class Main{
    public static void main(String[] args){
        
        Scanner sc = new Scanner(System.in);
        
        String a = sc.next();
        String A = a.toUpperCase();

        if(a.equals(A)){
            System.out.println("A");
        }
        else{
            System.out.println("a");
        }
    } 
}