import java.util.*;
import java.io.*;

public class Main {
    public static void main(String[] args) throws IOException {
        final BufferedWriter bw = new BufferedWriter(new OutputStreamWriter(System.out));
        final BufferedReader br = new BufferedReader(new InputStreamReader(System.in));

        char alpha = br.readLine().charAt(0);

        if (alpha > 96) {
            bw.write("a\n");
        } else {
            bw.write("A\n");
        }

        bw.close();
        br.close();
    }
} import java.util.*; util.* java import java.io.*; io.* java public class Main {
    public static void main(String[] args) throws IOException {
        final BufferedWriter bw = new BufferedWriter(new OutputStreamWriter(System.out));
        final BufferedReader br = new BufferedReader(new InputStreamReader(System.in));

        char alpha = br.readLine().charAt(0);

        if (alpha > 96) {
            bw.write("a\n");
        } else {
            bw.write("A\n");
        }

        bw.close();
        br.close();
    }
} Main public static void main(String[] args) throws IOException {
        final BufferedWriter bw = new BufferedWriter(new OutputStreamWriter(System.out));
        final BufferedReader br = new BufferedReader(new InputStreamReader(System.in));

        char alpha = br.readLine().charAt(0);

        if (alpha > 96) {
            bw.write("a\n");
        } else {
            bw.write("A\n");
        }

        bw.close();
        br.close();
    } main {
        final BufferedWriter bw = new BufferedWriter(new OutputStreamWriter(System.out));
        final BufferedReader br = new BufferedReader(new InputStreamReader(System.in));

        char alpha = br.readLine().charAt(0);

        if (alpha > 96) {
            bw.write("a\n");
        } else {
            bw.write("A\n");
        }

        bw.close();
        br.close();
    } final BufferedWriter bw = new BufferedWriter(new OutputStreamWriter(System.out)); bw new BufferedWriter(new OutputStreamWriter(System.out)) final BufferedReader br = new BufferedReader(new InputStreamReader(System.in)); br new BufferedReader(new InputStreamReader(System.in)) char alpha = br.readLine().charAt(0); alpha br.readLine().charAt(0) br.readLine().charAt br.readLine() br.readLine br 0 if (alpha > 96) {
            bw.write("a\n");
        } else {
            bw.write("A\n");
        } alpha > 96 alpha 96 {
            bw.write("a\n");
        } bw.write("a\n") bw.write bw "a\n" {
            bw.write("A\n");
        } bw.write("A\n") bw.write bw "A\n" bw.close() bw.close bw br.close() br.close br String[] args args public class Main {
    public static void main(String[] args) throws IOException {
        final BufferedWriter bw = new BufferedWriter(new OutputStreamWriter(System.out));
        final BufferedReader br = new BufferedReader(new InputStreamReader(System.in));

        char alpha = br.readLine().charAt(0);

        if (alpha > 96) {
            bw.write("a\n");
        } else {
            bw.write("A\n");
        }

        bw.close();
        br.close();
    }
} public class Main {
    public static void main(String[] args) throws IOException {
        final BufferedWriter bw = new BufferedWriter(new OutputStreamWriter(System.out));
        final BufferedReader br = new BufferedReader(new InputStreamReader(System.in));

        char alpha = br.readLine().charAt(0);

        if (alpha > 96) {
            bw.write("a\n");
        } else {
            bw.write("A\n");
        }

        bw.close();
        br.close();
    }
} Main
import java.util.*;
import java.io.*;

public class Main {
    public static void main(String[] args) throws IOException {
        final BufferedWriter bw = new BufferedWriter(new OutputStreamWriter(System.out));
        final BufferedReader br = new BufferedReader(new InputStreamReader(System.in));

        char alpha = br.readLine().charAt(0);

        if (alpha > 96) {
            bw.write("a\n");
        } else {
            bw.write("A\n");
        }

        bw.close();
        br.close();
    }
}
