import java.util.*;

public class Main {

    public static void main(String args[]) {

        // 入力
        Scanner sc = new Scanner(System.in);
        String s = sc.next();
        sc.close();

        // 主処理
        boolean judge = s.matches("[a-z]");
        String result = judge ? "a" : "A";

        // 出力
        System.out.println(result);
    }
} import java.util.*; util.* java public class Main {

    public static void main(String args[]) {

        // 入力
        Scanner sc = new Scanner(System.in);
        String s = sc.next();
        sc.close();

        // 主処理
        boolean judge = s.matches("[a-z]");
        String result = judge ? "a" : "A";

        // 出力
        System.out.println(result);
    }
} Main public static void main(String args[]) {

        // 入力
        Scanner sc = new Scanner(System.in);
        String s = sc.next();
        sc.close();

        // 主処理
        boolean judge = s.matches("[a-z]");
        String result = judge ? "a" : "A";

        // 出力
        System.out.println(result);
    } main {

        // 入力
        Scanner sc = new Scanner(System.in);
        String s = sc.next();
        sc.close();

        // 主処理
        boolean judge = s.matches("[a-z]");
        String result = judge ? "a" : "A";

        // 出力
        System.out.println(result);
    } Scanner sc = new Scanner(System.in); sc new Scanner(System.in) String s = sc.next(); s sc.next() sc.next sc sc.close() sc.close sc boolean judge = s.matches("[a-z]"); judge s.matches("[a-z]") s.matches s "[a-z]" String result = judge ? "a" : "A"; result judge ? "a" : "A" judge "a" "A" System.out.println(result) System.out.println System.out System System.out result String args[] args public class Main {

    public static void main(String args[]) {

        // 入力
        Scanner sc = new Scanner(System.in);
        String s = sc.next();
        sc.close();

        // 主処理
        boolean judge = s.matches("[a-z]");
        String result = judge ? "a" : "A";

        // 出力
        System.out.println(result);
    }
} public class Main {

    public static void main(String args[]) {

        // 入力
        Scanner sc = new Scanner(System.in);
        String s = sc.next();
        sc.close();

        // 主処理
        boolean judge = s.matches("[a-z]");
        String result = judge ? "a" : "A";

        // 出力
        System.out.println(result);
    }
} Main
import java.util.*;

public class Main {

    public static void main(String args[]) {

        // 入力
        Scanner sc = new Scanner(System.in);
        String s = sc.next();
        sc.close();

        // 主処理
        boolean judge = s.matches("[a-z]");
        String result = judge ? "a" : "A";

        // 出力
        System.out.println(result);
    }
}
