import java.util.Scanner;

public class Main {
    public static void main(String args[]){
        Scanner sc = new Scanner(System.in);

        char moji = sc.next().charAt(0);

        String ans = null;

        if(Character.isUpperCase(moji)){
            ans = "A";
        }else {
            ans = "a";
        }

        System.out.println(ans);

    }
} import java.util.Scanner; Scanner java.util public class Main {
    public static void main(String args[]){
        Scanner sc = new Scanner(System.in);

        char moji = sc.next().charAt(0);

        String ans = null;

        if(Character.isUpperCase(moji)){
            ans = "A";
        }else {
            ans = "a";
        }

        System.out.println(ans);

    }
} Main public static void main(String args[]){
        Scanner sc = new Scanner(System.in);

        char moji = sc.next().charAt(0);

        String ans = null;

        if(Character.isUpperCase(moji)){
            ans = "A";
        }else {
            ans = "a";
        }

        System.out.println(ans);

    } main {
        Scanner sc = new Scanner(System.in);

        char moji = sc.next().charAt(0);

        String ans = null;

        if(Character.isUpperCase(moji)){
            ans = "A";
        }else {
            ans = "a";
        }

        System.out.println(ans);

    } Scanner sc = new Scanner(System.in); sc new Scanner(System.in) char moji = sc.next().charAt(0); moji sc.next().charAt(0) sc.next().charAt sc.next() sc.next sc 0 String ans = null; ans null if(Character.isUpperCase(moji)){
            ans = "A";
        }else {
            ans = "a";
        } Character.isUpperCase(moji) Character.isUpperCase Character moji {
            ans = "A";
        } ans = "A" ans "A" {
            ans = "a";
        } 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);

        char moji = sc.next().charAt(0);

        String ans = null;

        if(Character.isUpperCase(moji)){
            ans = "A";
        }else {
            ans = "a";
        }

        System.out.println(ans);

    }
} public class Main {
    public static void main(String args[]){
        Scanner sc = new Scanner(System.in);

        char moji = sc.next().charAt(0);

        String ans = null;

        if(Character.isUpperCase(moji)){
            ans = "A";
        }else {
            ans = "a";
        }

        System.out.println(ans);

    }
} Main
import java.util.Scanner;

public class Main {
    public static void main(String args[]){
        Scanner sc = new Scanner(System.in);

        char moji = sc.next().charAt(0);

        String ans = null;

        if(Character.isUpperCase(moji)){
            ans = "A";
        }else {
            ans = "a";
        }

        System.out.println(ans);

    }
}
