import java.io.*;
import java.util.Scanner;
import java.util.Arrays;
import java.util.ArrayList;
import java.math.BigDecimal;

public class Main{

    public static void main(String[] args){
        //START

        Scanner sc=new Scanner(System.in);

        String str=sc.next();
        char[] c = str.toCharArray();

        int code = (int)c[0];

        if(code<91){
            System.out.println("A");
        }else{
            System.out.println("a");
        }

        //System.out.println(code);


        //END
    }
}


 import java.io.*; io.* java import java.util.Scanner; Scanner java.util import java.util.Arrays; Arrays java.util import java.util.ArrayList; ArrayList java.util import java.math.BigDecimal; BigDecimal java.math public class Main{

    public static void main(String[] args){
        //START

        Scanner sc=new Scanner(System.in);

        String str=sc.next();
        char[] c = str.toCharArray();

        int code = (int)c[0];

        if(code<91){
            System.out.println("A");
        }else{
            System.out.println("a");
        }

        //System.out.println(code);


        //END
    }
} Main public static void main(String[] args){
        //START

        Scanner sc=new Scanner(System.in);

        String str=sc.next();
        char[] c = str.toCharArray();

        int code = (int)c[0];

        if(code<91){
            System.out.println("A");
        }else{
            System.out.println("a");
        }

        //System.out.println(code);


        //END
    } main {
        //START

        Scanner sc=new Scanner(System.in);

        String str=sc.next();
        char[] c = str.toCharArray();

        int code = (int)c[0];

        if(code<91){
            System.out.println("A");
        }else{
            System.out.println("a");
        }

        //System.out.println(code);


        //END
    } Scanner sc=new Scanner(System.in); sc new Scanner(System.in) String str=sc.next(); str sc.next() sc.next sc char[] c = str.toCharArray(); c str.toCharArray() str.toCharArray str int code = (int)c[0]; code (int)c[0] c 0 if(code<91){
            System.out.println("A");
        }else{
            System.out.println("a");
        } code<91 code 91 {
            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){
        //START

        Scanner sc=new Scanner(System.in);

        String str=sc.next();
        char[] c = str.toCharArray();

        int code = (int)c[0];

        if(code<91){
            System.out.println("A");
        }else{
            System.out.println("a");
        }

        //System.out.println(code);


        //END
    }
} public class Main{

    public static void main(String[] args){
        //START

        Scanner sc=new Scanner(System.in);

        String str=sc.next();
        char[] c = str.toCharArray();

        int code = (int)c[0];

        if(code<91){
            System.out.println("A");
        }else{
            System.out.println("a");
        }

        //System.out.println(code);


        //END
    }
} Main
import java.io.*;
import java.util.Scanner;
import java.util.Arrays;
import java.util.ArrayList;
import java.math.BigDecimal;

public class Main{

    public static void main(String[] args){
        //START

        Scanner sc=new Scanner(System.in);

        String str=sc.next();
        char[] c = str.toCharArray();

        int code = (int)c[0];

        if(code<91){
            System.out.println("A");
        }else{
            System.out.println("a");
        }

        //System.out.println(code);


        //END
    }
}



