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

public class Main {
    public static void main(String[] args) throws Exception {
        BufferedReader buffer = new BufferedReader(new InputStreamReader(System.in));
        StringBuilder sb = new StringBuilder();
        char ch = buffer.readLine().charAt(0);
        if (Character.isUpperCase(ch))
            sb.append("A\n");
        else
            sb.append("a\n");
        System.out.println(sb);
    }
} import java.io.*; io.* java import java.util.*; util.* java public class Main {
    public static void main(String[] args) throws Exception {
        BufferedReader buffer = new BufferedReader(new InputStreamReader(System.in));
        StringBuilder sb = new StringBuilder();
        char ch = buffer.readLine().charAt(0);
        if (Character.isUpperCase(ch))
            sb.append("A\n");
        else
            sb.append("a\n");
        System.out.println(sb);
    }
} Main public static void main(String[] args) throws Exception {
        BufferedReader buffer = new BufferedReader(new InputStreamReader(System.in));
        StringBuilder sb = new StringBuilder();
        char ch = buffer.readLine().charAt(0);
        if (Character.isUpperCase(ch))
            sb.append("A\n");
        else
            sb.append("a\n");
        System.out.println(sb);
    } main {
        BufferedReader buffer = new BufferedReader(new InputStreamReader(System.in));
        StringBuilder sb = new StringBuilder();
        char ch = buffer.readLine().charAt(0);
        if (Character.isUpperCase(ch))
            sb.append("A\n");
        else
            sb.append("a\n");
        System.out.println(sb);
    } BufferedReader buffer = new BufferedReader(new InputStreamReader(System.in)); buffer new BufferedReader(new InputStreamReader(System.in)) StringBuilder sb = new StringBuilder(); sb new StringBuilder() char ch = buffer.readLine().charAt(0); ch buffer.readLine().charAt(0) buffer.readLine().charAt buffer.readLine() buffer.readLine buffer 0 if (Character.isUpperCase(ch))
            sb.append("A\n");
        else
            sb.append("a\n"); Character.isUpperCase(ch) Character.isUpperCase Character ch sb.append("A\n") sb.append sb "A\n" sb.append("a\n") sb.append sb "a\n" System.out.println(sb) System.out.println System.out System System.out sb String[] args args public class Main {
    public static void main(String[] args) throws Exception {
        BufferedReader buffer = new BufferedReader(new InputStreamReader(System.in));
        StringBuilder sb = new StringBuilder();
        char ch = buffer.readLine().charAt(0);
        if (Character.isUpperCase(ch))
            sb.append("A\n");
        else
            sb.append("a\n");
        System.out.println(sb);
    }
} public class Main {
    public static void main(String[] args) throws Exception {
        BufferedReader buffer = new BufferedReader(new InputStreamReader(System.in));
        StringBuilder sb = new StringBuilder();
        char ch = buffer.readLine().charAt(0);
        if (Character.isUpperCase(ch))
            sb.append("A\n");
        else
            sb.append("a\n");
        System.out.println(sb);
    }
} Main
import java.io.*;
import java.util.*;

public class Main {
    public static void main(String[] args) throws Exception {
        BufferedReader buffer = new BufferedReader(new InputStreamReader(System.in));
        StringBuilder sb = new StringBuilder();
        char ch = buffer.readLine().charAt(0);
        if (Character.isUpperCase(ch))
            sb.append("A\n");
        else
            sb.append("a\n");
        System.out.println(sb);
    }
}
