import java.util.*;
import java.lang.*;
 
class Main{
	public static void main(String args[]){
    Scanner sc = new Scanner(System.in);
    char line = sc.next().toCharArray()[0];
    if(Character.isLowerCase(line)){
    	System.out.println("a");
    	}
      else {
      	System.out.println("A");
      }
    }
} import java.util.*; util.* java import java.lang.*; lang.* java class Main{
	public static void main(String args[]){
    Scanner sc = new Scanner(System.in);
    char line = sc.next().toCharArray()[0];
    if(Character.isLowerCase(line)){
    	System.out.println("a");
    	}
      else {
      	System.out.println("A");
      }
    }
} Main public static void main(String args[]){
    Scanner sc = new Scanner(System.in);
    char line = sc.next().toCharArray()[0];
    if(Character.isLowerCase(line)){
    	System.out.println("a");
    	}
      else {
      	System.out.println("A");
      }
    } main {
    Scanner sc = new Scanner(System.in);
    char line = sc.next().toCharArray()[0];
    if(Character.isLowerCase(line)){
    	System.out.println("a");
    	}
      else {
      	System.out.println("A");
      }
    } Scanner sc = new Scanner(System.in); sc new Scanner(System.in) char line = sc.next().toCharArray()[0]; line sc.next().toCharArray()[0] sc.next().toCharArray() sc.next().toCharArray sc.next() sc.next sc 0 if(Character.isLowerCase(line)){
    	System.out.println("a");
    	}
      else {
      	System.out.println("A");
      } Character.isLowerCase(line) Character.isLowerCase Character line {
    	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
import java.util.*;
import java.lang.*;
 
class Main{
	public static void main(String args[]){
    Scanner sc = new Scanner(System.in);
    char line = sc.next().toCharArray()[0];
    if(Character.isLowerCase(line)){
    	System.out.println("a");
    	}
      else {
      	System.out.println("A");
      }
    }
}