import java.util.Scanner;
 
public class Main {
   public static void main(String[] args) {
       Scanner sc = new Scanner(System.in);
     
        //String[] ALFA = {"A","B","C","D","E","F","G","H","I","J","K","L","M","N","O","P","Q","R","S","T","U","V","W","X","Y","Z"};
        //String[] alfa = {"a","b","c","d","e","f","g","h","i","j","k","l","m","n","o","p","q","r","s","t","u","v","w","x","y","z"};
        
        String S = sc.nextLine();
        
        //Sに大文字が含まれるとき
        if(S.toUpperCase() == S) { 
          System.out.println("A");
        } else {
          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[] ALFA = {"A","B","C","D","E","F","G","H","I","J","K","L","M","N","O","P","Q","R","S","T","U","V","W","X","Y","Z"};
        //String[] alfa = {"a","b","c","d","e","f","g","h","i","j","k","l","m","n","o","p","q","r","s","t","u","v","w","x","y","z"};
        
        String S = sc.nextLine();
        
        //Sに大文字が含まれるとき
        if(S.toUpperCase() == S) { 
          System.out.println("A");
        } else {
          System.out.println("a");
        }
   }
} Main public static void main(String[] args) {
       Scanner sc = new Scanner(System.in);
     
        //String[] ALFA = {"A","B","C","D","E","F","G","H","I","J","K","L","M","N","O","P","Q","R","S","T","U","V","W","X","Y","Z"};
        //String[] alfa = {"a","b","c","d","e","f","g","h","i","j","k","l","m","n","o","p","q","r","s","t","u","v","w","x","y","z"};
        
        String S = sc.nextLine();
        
        //Sに大文字が含まれるとき
        if(S.toUpperCase() == S) { 
          System.out.println("A");
        } else {
          System.out.println("a");
        }
   } main {
       Scanner sc = new Scanner(System.in);
     
        //String[] ALFA = {"A","B","C","D","E","F","G","H","I","J","K","L","M","N","O","P","Q","R","S","T","U","V","W","X","Y","Z"};
        //String[] alfa = {"a","b","c","d","e","f","g","h","i","j","k","l","m","n","o","p","q","r","s","t","u","v","w","x","y","z"};
        
        String S = sc.nextLine();
        
        //Sに大文字が含まれるとき
        if(S.toUpperCase() == S) { 
          System.out.println("A");
        } else {
          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 {
          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" {
          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[] ALFA = {"A","B","C","D","E","F","G","H","I","J","K","L","M","N","O","P","Q","R","S","T","U","V","W","X","Y","Z"};
        //String[] alfa = {"a","b","c","d","e","f","g","h","i","j","k","l","m","n","o","p","q","r","s","t","u","v","w","x","y","z"};
        
        String S = sc.nextLine();
        
        //Sに大文字が含まれるとき
        if(S.toUpperCase() == S) { 
          System.out.println("A");
        } else {
          System.out.println("a");
        }
   }
} public class Main {
   public static void main(String[] args) {
       Scanner sc = new Scanner(System.in);
     
        //String[] ALFA = {"A","B","C","D","E","F","G","H","I","J","K","L","M","N","O","P","Q","R","S","T","U","V","W","X","Y","Z"};
        //String[] alfa = {"a","b","c","d","e","f","g","h","i","j","k","l","m","n","o","p","q","r","s","t","u","v","w","x","y","z"};
        
        String S = sc.nextLine();
        
        //Sに大文字が含まれるとき
        if(S.toUpperCase() == S) { 
          System.out.println("A");
        } else {
          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[] ALFA = {"A","B","C","D","E","F","G","H","I","J","K","L","M","N","O","P","Q","R","S","T","U","V","W","X","Y","Z"};
        //String[] alfa = {"a","b","c","d","e","f","g","h","i","j","k","l","m","n","o","p","q","r","s","t","u","v","w","x","y","z"};
        
        String S = sc.nextLine();
        
        //Sに大文字が含まれるとき
        if(S.toUpperCase() == S) { 
          System.out.println("A");
        } else {
          System.out.println("a");
        }
   }
}