import java.util.*;

public class Main {
    public static void main(String[] args) throws Exception {
        
        Scanner sc = new Scanner(System.in);
        String alpha = sc.next();
        
        if (alpha.toUpperCase().equals(alpha)) {
             System.out.println("A");
        } else {
            System.out.println("a");
        }
       
    }
} import java.util.*; util.* java public class Main {
    public static void main(String[] args) throws Exception {
        
        Scanner sc = new Scanner(System.in);
        String alpha = sc.next();
        
        if (alpha.toUpperCase().equals(alpha)) {
             System.out.println("A");
        } else {
            System.out.println("a");
        }
       
    }
} Main public static void main(String[] args) throws Exception {
        
        Scanner sc = new Scanner(System.in);
        String alpha = sc.next();
        
        if (alpha.toUpperCase().equals(alpha)) {
             System.out.println("A");
        } else {
            System.out.println("a");
        }
       
    } main {
        
        Scanner sc = new Scanner(System.in);
        String alpha = sc.next();
        
        if (alpha.toUpperCase().equals(alpha)) {
             System.out.println("A");
        } else {
            System.out.println("a");
        }
       
    } Scanner sc = new Scanner(System.in); sc new Scanner(System.in) String alpha = sc.next(); alpha sc.next() sc.next sc if (alpha.toUpperCase().equals(alpha)) {
             System.out.println("A");
        } else {
            System.out.println("a");
        } alpha.toUpperCase().equals(alpha) alpha.toUpperCase().equals alpha.toUpperCase() alpha.toUpperCase alpha alpha {
             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 public class Main {
    public static void main(String[] args) throws Exception {
        
        Scanner sc = new Scanner(System.in);
        String alpha = sc.next();
        
        if (alpha.toUpperCase().equals(alpha)) {
             System.out.println("A");
        } else {
            System.out.println("a");
        }
       
    }
} public class Main {
    public static void main(String[] args) throws Exception {
        
        Scanner sc = new Scanner(System.in);
        String alpha = sc.next();
        
        if (alpha.toUpperCase().equals(alpha)) {
             System.out.println("A");
        } else {
            System.out.println("a");
        }
       
    }
} Main
import java.util.*;

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