import java.util.Scanner;
public class Main {
   public static void main(String[] args) {
       Scanner sc = new Scanner(System.in);
       String S = sc.nextLine();
       if (S.toUpperCase() == S) {
         System.out.println("A");
       } else if (S.toLowerCase() == S) {
         System.out.println("a");
       }
   }
} import java.util.Scanner; Scanner java.util public class Main {
   public static void main(String[] args) {
       Scanner sc = new Scanner(System.in);
       String S = sc.nextLine();
       if (S.toUpperCase() == S) {
         System.out.println("A");
       } else if (S.toLowerCase() == S) {
         System.out.println("a");
       }
   }
} Main public static void main(String[] args) {
       Scanner sc = new Scanner(System.in);
       String S = sc.nextLine();
       if (S.toUpperCase() == S) {
         System.out.println("A");
       } else if (S.toLowerCase() == S) {
         System.out.println("a");
       }
   } main {
       Scanner sc = new Scanner(System.in);
       String S = sc.nextLine();
       if (S.toUpperCase() == S) {
         System.out.println("A");
       } else if (S.toLowerCase() == S) {
         System.out.println("a");
       }
   } Scanner sc = new Scanner(System.in); sc new Scanner(System.in) String S = sc.nextLine(); S sc.nextLine() sc.nextLine sc if (S.toUpperCase() == S) {
         System.out.println("A");
       } else if (S.toLowerCase() == S) {
         System.out.println("a");
       } S.toUpperCase() == S S.toUpperCase() S.toUpperCase S S {
         System.out.println("A");
       } System.out.println("A") System.out.println System.out System System.out "A" if (S.toLowerCase() == S) {
         System.out.println("a");
       } S.toLowerCase() == S S.toLowerCase() S.toLowerCase S S {
         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);
       String S = sc.nextLine();
       if (S.toUpperCase() == S) {
         System.out.println("A");
       } else if (S.toLowerCase() == S) {
         System.out.println("a");
       }
   }
} public class Main {
   public static void main(String[] args) {
       Scanner sc = new Scanner(System.in);
       String S = sc.nextLine();
       if (S.toUpperCase() == S) {
         System.out.println("A");
       } else if (S.toLowerCase() == S) {
         System.out.println("a");
       }
   }
} Main
import java.util.Scanner;
public class Main {
   public static void main(String[] args) {
       Scanner sc = new Scanner(System.in);
       String S = sc.nextLine();
       if (S.toUpperCase() == S) {
         System.out.println("A");
       } else if (S.toLowerCase() == S) {
         System.out.println("a");
       }
   }
}