import java.util.*;
public class Main {
	public static void main(String[] args){
		Scanner sc = new Scanner(System.in);
		String s = sc.next();
		
        String str[] = {"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"};
        for(int i=0;i<26;i++){if(s.equals(str[i])){System.out.println("a");break;}
                              else{if(i==25){System.out.println("A");}}
                             }
		
		
	}
} import java.util.*; util.* java public class Main {
	public static void main(String[] args){
		Scanner sc = new Scanner(System.in);
		String s = sc.next();
		
        String str[] = {"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"};
        for(int i=0;i<26;i++){if(s.equals(str[i])){System.out.println("a");break;}
                              else{if(i==25){System.out.println("A");}}
                             }
		
		
	}
} Main public static void main(String[] args){
		Scanner sc = new Scanner(System.in);
		String s = sc.next();
		
        String str[] = {"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"};
        for(int i=0;i<26;i++){if(s.equals(str[i])){System.out.println("a");break;}
                              else{if(i==25){System.out.println("A");}}
                             }
		
		
	} main {
		Scanner sc = new Scanner(System.in);
		String s = sc.next();
		
        String str[] = {"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"};
        for(int i=0;i<26;i++){if(s.equals(str[i])){System.out.println("a");break;}
                              else{if(i==25){System.out.println("A");}}
                             }
		
		
	} Scanner sc = new Scanner(System.in); sc new Scanner(System.in) String s = sc.next(); s sc.next() sc.next sc String str[] = {"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"}; str {"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"} "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" for(int i=0;i<26;i++){if(s.equals(str[i])){System.out.println("a");break;}
                              else{if(i==25){System.out.println("A");}}
                             } int i=0; int i=0; i 0 i<26 i 26 i++ i++ i {if(s.equals(str[i])){System.out.println("a");break;}
                              else{if(i==25){System.out.println("A");}}
                             } {if(s.equals(str[i])){System.out.println("a");break;}
                              else{if(i==25){System.out.println("A");}}
                             } if(s.equals(str[i])){System.out.println("a");break;}
                              else{if(i==25){System.out.println("A");}} s.equals(str[i]) s.equals s str[i] str i {System.out.println("a");break;} System.out.println("a") System.out.println System.out System System.out "a" break; {if(i==25){System.out.println("A");}} if(i==25){System.out.println("A");} i==25 i 25 {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.next();
		
        String str[] = {"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"};
        for(int i=0;i<26;i++){if(s.equals(str[i])){System.out.println("a");break;}
                              else{if(i==25){System.out.println("A");}}
                             }
		
		
	}
} public class Main {
	public static void main(String[] args){
		Scanner sc = new Scanner(System.in);
		String s = sc.next();
		
        String str[] = {"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"};
        for(int i=0;i<26;i++){if(s.equals(str[i])){System.out.println("a");break;}
                              else{if(i==25){System.out.println("A");}}
                             }
		
		
	}
} Main
import java.util.*;
public class Main {
	public static void main(String[] args){
		Scanner sc = new Scanner(System.in);
		String s = sc.next();
		
        String str[] = {"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"};
        for(int i=0;i<26;i++){if(s.equals(str[i])){System.out.println("a");break;}
                              else{if(i==25){System.out.println("A");}}
                             }
		
		
	}
}
