import java.io.BufferedReader;
import java.io.IOException;
import java.io.PrintWriter;
import java.util.StringTokenizer;

public class Main {
    
    public static void main(String[] args) throws IOException {
        BufferedReader br = new BufferedReader(new java.io.InputStreamReader(System.in));
        PrintWriter pw = new PrintWriter(System.out);
        StringTokenizer st = new StringTokenizer(br.readLine());

        String target = st.nextToken();

        if(Character.isUpperCase(target.charAt(0))) {
            pw.println("A");
        } else {
            pw.println("a");
        }

        br.close();
        pw.close();
    }
} import java.io.BufferedReader; BufferedReader java.io import java.io.IOException; IOException java.io import java.io.PrintWriter; PrintWriter java.io import java.util.StringTokenizer; StringTokenizer java.util public class Main {
    
    public static void main(String[] args) throws IOException {
        BufferedReader br = new BufferedReader(new java.io.InputStreamReader(System.in));
        PrintWriter pw = new PrintWriter(System.out);
        StringTokenizer st = new StringTokenizer(br.readLine());

        String target = st.nextToken();

        if(Character.isUpperCase(target.charAt(0))) {
            pw.println("A");
        } else {
            pw.println("a");
        }

        br.close();
        pw.close();
    }
} Main public static void main(String[] args) throws IOException {
        BufferedReader br = new BufferedReader(new java.io.InputStreamReader(System.in));
        PrintWriter pw = new PrintWriter(System.out);
        StringTokenizer st = new StringTokenizer(br.readLine());

        String target = st.nextToken();

        if(Character.isUpperCase(target.charAt(0))) {
            pw.println("A");
        } else {
            pw.println("a");
        }

        br.close();
        pw.close();
    } main {
        BufferedReader br = new BufferedReader(new java.io.InputStreamReader(System.in));
        PrintWriter pw = new PrintWriter(System.out);
        StringTokenizer st = new StringTokenizer(br.readLine());

        String target = st.nextToken();

        if(Character.isUpperCase(target.charAt(0))) {
            pw.println("A");
        } else {
            pw.println("a");
        }

        br.close();
        pw.close();
    } BufferedReader br = new BufferedReader(new java.io.InputStreamReader(System.in)); br new BufferedReader(new java.io.InputStreamReader(System.in)) PrintWriter pw = new PrintWriter(System.out); pw new PrintWriter(System.out) StringTokenizer st = new StringTokenizer(br.readLine()); st new StringTokenizer(br.readLine()) String target = st.nextToken(); target st.nextToken() st.nextToken st if(Character.isUpperCase(target.charAt(0))) {
            pw.println("A");
        } else {
            pw.println("a");
        } Character.isUpperCase(target.charAt(0)) Character.isUpperCase Character target.charAt(0) target.charAt target 0 {
            pw.println("A");
        } pw.println("A") pw.println pw "A" {
            pw.println("a");
        } pw.println("a") pw.println pw "a" br.close() br.close br pw.close() pw.close pw String[] args args public class Main {
    
    public static void main(String[] args) throws IOException {
        BufferedReader br = new BufferedReader(new java.io.InputStreamReader(System.in));
        PrintWriter pw = new PrintWriter(System.out);
        StringTokenizer st = new StringTokenizer(br.readLine());

        String target = st.nextToken();

        if(Character.isUpperCase(target.charAt(0))) {
            pw.println("A");
        } else {
            pw.println("a");
        }

        br.close();
        pw.close();
    }
} public class Main {
    
    public static void main(String[] args) throws IOException {
        BufferedReader br = new BufferedReader(new java.io.InputStreamReader(System.in));
        PrintWriter pw = new PrintWriter(System.out);
        StringTokenizer st = new StringTokenizer(br.readLine());

        String target = st.nextToken();

        if(Character.isUpperCase(target.charAt(0))) {
            pw.println("A");
        } else {
            pw.println("a");
        }

        br.close();
        pw.close();
    }
} Main
import java.io.BufferedReader;
import java.io.IOException;
import java.io.PrintWriter;
import java.util.StringTokenizer;

public class Main {
    
    public static void main(String[] args) throws IOException {
        BufferedReader br = new BufferedReader(new java.io.InputStreamReader(System.in));
        PrintWriter pw = new PrintWriter(System.out);
        StringTokenizer st = new StringTokenizer(br.readLine());

        String target = st.nextToken();

        if(Character.isUpperCase(target.charAt(0))) {
            pw.println("A");
        } else {
            pw.println("a");
        }

        br.close();
        pw.close();
    }
}