import java.io.BufferedReader;
import java.io.IOException;
import java.io.InputStreamReader;

public class Main {
    public static void main(String args[]) throws IOException {

	BufferedReader br = new BufferedReader(new InputStreamReader(System.in));
	char ch[] = br.readLine().toCharArray();
	if (Character.isUpperCase(ch[0])) {
	    System.out.println("A");
	} else {
	    System.out.println("a");
	}
    }
} import java.io.BufferedReader; BufferedReader java.io import java.io.IOException; IOException java.io import java.io.InputStreamReader; InputStreamReader java.io public class Main {
    public static void main(String args[]) throws IOException {

	BufferedReader br = new BufferedReader(new InputStreamReader(System.in));
	char ch[] = br.readLine().toCharArray();
	if (Character.isUpperCase(ch[0])) {
	    System.out.println("A");
	} else {
	    System.out.println("a");
	}
    }
} Main public static void main(String args[]) throws IOException {

	BufferedReader br = new BufferedReader(new InputStreamReader(System.in));
	char ch[] = br.readLine().toCharArray();
	if (Character.isUpperCase(ch[0])) {
	    System.out.println("A");
	} else {
	    System.out.println("a");
	}
    } main {

	BufferedReader br = new BufferedReader(new InputStreamReader(System.in));
	char ch[] = br.readLine().toCharArray();
	if (Character.isUpperCase(ch[0])) {
	    System.out.println("A");
	} else {
	    System.out.println("a");
	}
    } BufferedReader br = new BufferedReader(new InputStreamReader(System.in)); br new BufferedReader(new InputStreamReader(System.in)) char ch[] = br.readLine().toCharArray(); ch br.readLine().toCharArray() br.readLine().toCharArray br.readLine() br.readLine br if (Character.isUpperCase(ch[0])) {
	    System.out.println("A");
	} else {
	    System.out.println("a");
	} Character.isUpperCase(ch[0]) Character.isUpperCase Character ch[0] ch 0 {
	    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 IOException {

	BufferedReader br = new BufferedReader(new InputStreamReader(System.in));
	char ch[] = br.readLine().toCharArray();
	if (Character.isUpperCase(ch[0])) {
	    System.out.println("A");
	} else {
	    System.out.println("a");
	}
    }
} public class Main {
    public static void main(String args[]) throws IOException {

	BufferedReader br = new BufferedReader(new InputStreamReader(System.in));
	char ch[] = br.readLine().toCharArray();
	if (Character.isUpperCase(ch[0])) {
	    System.out.println("A");
	} else {
	    System.out.println("a");
	}
    }
} Main
import java.io.BufferedReader;
import java.io.IOException;
import java.io.InputStreamReader;

public class Main {
    public static void main(String args[]) throws IOException {

	BufferedReader br = new BufferedReader(new InputStreamReader(System.in));
	char ch[] = br.readLine().toCharArray();
	if (Character.isUpperCase(ch[0])) {
	    System.out.println("A");
	} else {
	    System.out.println("a");
	}
    }
}