import java.util.*;
class Main{
  public static void main(String[] args){
Scanner sc=new Scanner(System.in);
    char a=sc.next().charAt(0);
   int c=a;
    if(c>=65&&c<=90){
    
System.out.println("A");
    }else if(c>=97&&c<=122){
System.out.println("a");
    }
  }
} import java.util.*; util.* java class Main{
  public static void main(String[] args){
Scanner sc=new Scanner(System.in);
    char a=sc.next().charAt(0);
   int c=a;
    if(c>=65&&c<=90){
    
System.out.println("A");
    }else if(c>=97&&c<=122){
System.out.println("a");
    }
  }
} Main public static void main(String[] args){
Scanner sc=new Scanner(System.in);
    char a=sc.next().charAt(0);
   int c=a;
    if(c>=65&&c<=90){
    
System.out.println("A");
    }else if(c>=97&&c<=122){
System.out.println("a");
    }
  } main {
Scanner sc=new Scanner(System.in);
    char a=sc.next().charAt(0);
   int c=a;
    if(c>=65&&c<=90){
    
System.out.println("A");
    }else if(c>=97&&c<=122){
System.out.println("a");
    }
  } Scanner sc=new Scanner(System.in); sc new Scanner(System.in) char a=sc.next().charAt(0); a sc.next().charAt(0) sc.next().charAt sc.next() sc.next sc 0 int c=a; c a if(c>=65&&c<=90){
    
System.out.println("A");
    }else if(c>=97&&c<=122){
System.out.println("a");
    } c>=65&&c<=90 c>=65 c 65 c<=90 c 90 {
    
System.out.println("A");
    } System.out.println("A") System.out.println System.out System System.out "A" if(c>=97&&c<=122){
System.out.println("a");
    } c>=97&&c<=122 c>=97 c 97 c<=122 c 122 {
System.out.println("a");
    } System.out.println("a") System.out.println System.out System System.out "a" String[] args args
import java.util.*;
class Main{
  public static void main(String[] args){
Scanner sc=new Scanner(System.in);
    char a=sc.next().charAt(0);
   int c=a;
    if(c>=65&&c<=90){
    
System.out.println("A");
    }else if(c>=97&&c<=122){
System.out.println("a");
    }
  }
}