import java.util.*;

public class Main {
    public static void main(String[] args) throws Exception {
      	Scanner sc = new Scanner(System.in);
      	String str = sc.next();
        if( Character.isUpperCase( str.charAt(0) ) ) {
    		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 str = sc.next();
        if( Character.isUpperCase( str.charAt(0) ) ) {
    		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 str = sc.next();
        if( Character.isUpperCase( str.charAt(0) ) ) {
    		System.out.println("A");
		} else {
    		System.out.println("a");
		}
    } main {
      	Scanner sc = new Scanner(System.in);
      	String str = sc.next();
        if( Character.isUpperCase( str.charAt(0) ) ) {
    		System.out.println("A");
		} else {
    		System.out.println("a");
		}
    } Scanner sc = new Scanner(System.in); sc new Scanner(System.in) String str = sc.next(); str sc.next() sc.next sc if( Character.isUpperCase( str.charAt(0) ) ) {
    		System.out.println("A");
		} else {
    		System.out.println("a");
		} Character.isUpperCase( str.charAt(0) ) Character.isUpperCase Character str.charAt(0) str.charAt str 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 Exception {
      	Scanner sc = new Scanner(System.in);
      	String str = sc.next();
        if( Character.isUpperCase( str.charAt(0) ) ) {
    		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 str = sc.next();
        if( Character.isUpperCase( str.charAt(0) ) ) {
    		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 str = sc.next();
        if( Character.isUpperCase( str.charAt(0) ) ) {
    		System.out.println("A");
		} else {
    		System.out.println("a");
		}
    }
}