import java.util.*;
import java.io.*;

public class Main {
    public static void main(String[] args) {
        Scanner sc = new Scanner(System.in);
        char c = sc.next().charAt(0);
        if (c >= 'a' && c <= 'z') {
            System.out.println('a');
        } else {
            System.out.println('A');
        }
    }
} import java.util.*; util.* java import java.io.*; io.* java public class Main {
    public static void main(String[] args) {
        Scanner sc = new Scanner(System.in);
        char c = sc.next().charAt(0);
        if (c >= 'a' && c <= 'z') {
            System.out.println('a');
        } else {
            System.out.println('A');
        }
    }
} Main public static void main(String[] args) {
        Scanner sc = new Scanner(System.in);
        char c = sc.next().charAt(0);
        if (c >= 'a' && c <= 'z') {
            System.out.println('a');
        } else {
            System.out.println('A');
        }
    } main {
        Scanner sc = new Scanner(System.in);
        char c = sc.next().charAt(0);
        if (c >= 'a' && c <= 'z') {
            System.out.println('a');
        } else {
            System.out.println('A');
        }
    } Scanner sc = new Scanner(System.in); sc new Scanner(System.in) char c = sc.next().charAt(0); c sc.next().charAt(0) sc.next().charAt sc.next() sc.next sc 0 if (c >= 'a' && c <= 'z') {
            System.out.println('a');
        } else {
            System.out.println('A');
        } c >= 'a' && c <= 'z' c >= 'a' c 'a' c <= 'z' c 'z' {
            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) {
        Scanner sc = new Scanner(System.in);
        char c = sc.next().charAt(0);
        if (c >= 'a' && c <= 'z') {
            System.out.println('a');
        } else {
            System.out.println('A');
        }
    }
} public class Main {
    public static void main(String[] args) {
        Scanner sc = new Scanner(System.in);
        char c = sc.next().charAt(0);
        if (c >= 'a' && c <= 'z') {
            System.out.println('a');
        } else {
            System.out.println('A');
        }
    }
} Main
import java.util.*;
import java.io.*;

public class Main {
    public static void main(String[] args) {
        Scanner sc = new Scanner(System.in);
        char c = sc.next().charAt(0);
        if (c >= 'a' && c <= 'z') {
            System.out.println('a');
        } else {
            System.out.println('A');
        }
    }
}