import java.util.*;
public class Main{
    public static void main(String[] args) {
        Scanner sc = new Scanner(System.in);
        char A = sc.next().charAt(0);
        char [] bi = new char[26];
        char [] sm = new char[26];
        char AA = 'A';
        char a = 'a';
        char anc = 'a';
        for(int i = 0;i < 26;i++){
            bi[i] = AA++;
            sm[i] = a++;
        }
        for(int i = 0;i < 26;i++){
            if(bi[i] == A){
                anc = 'A';
            }
        }
        System.out.println(anc);
    }
} import java.util.*; util.* java public class Main{
    public static void main(String[] args) {
        Scanner sc = new Scanner(System.in);
        char A = sc.next().charAt(0);
        char [] bi = new char[26];
        char [] sm = new char[26];
        char AA = 'A';
        char a = 'a';
        char anc = 'a';
        for(int i = 0;i < 26;i++){
            bi[i] = AA++;
            sm[i] = a++;
        }
        for(int i = 0;i < 26;i++){
            if(bi[i] == A){
                anc = 'A';
            }
        }
        System.out.println(anc);
    }
} Main public static void main(String[] args) {
        Scanner sc = new Scanner(System.in);
        char A = sc.next().charAt(0);
        char [] bi = new char[26];
        char [] sm = new char[26];
        char AA = 'A';
        char a = 'a';
        char anc = 'a';
        for(int i = 0;i < 26;i++){
            bi[i] = AA++;
            sm[i] = a++;
        }
        for(int i = 0;i < 26;i++){
            if(bi[i] == A){
                anc = 'A';
            }
        }
        System.out.println(anc);
    } main {
        Scanner sc = new Scanner(System.in);
        char A = sc.next().charAt(0);
        char [] bi = new char[26];
        char [] sm = new char[26];
        char AA = 'A';
        char a = 'a';
        char anc = 'a';
        for(int i = 0;i < 26;i++){
            bi[i] = AA++;
            sm[i] = a++;
        }
        for(int i = 0;i < 26;i++){
            if(bi[i] == A){
                anc = 'A';
            }
        }
        System.out.println(anc);
    } Scanner sc = new Scanner(System.in); sc new Scanner(System.in) char A = sc.next().charAt(0); A sc.next().charAt(0) sc.next().charAt sc.next() sc.next sc 0 char [] bi = new char[26]; bi new char[26] 26 char [] sm = new char[26]; sm new char[26] 26 char AA = 'A'; AA 'A' char a = 'a'; a 'a' char anc = 'a'; anc 'a' for(int i = 0;i < 26;i++){
            bi[i] = AA++;
            sm[i] = a++;
        } int i = 0; int i = 0; i 0 i < 26 i 26 i++ i++ i {
            bi[i] = AA++;
            sm[i] = a++;
        } {
            bi[i] = AA++;
            sm[i] = a++;
        } bi[i] = AA++ bi[i] bi i AA++ AA sm[i] = a++ sm[i] sm i a++ a for(int i = 0;i < 26;i++){
            if(bi[i] == A){
                anc = 'A';
            }
        } int i = 0; int i = 0; i 0 i < 26 i 26 i++ i++ i {
            if(bi[i] == A){
                anc = 'A';
            }
        } {
            if(bi[i] == A){
                anc = 'A';
            }
        } if(bi[i] == A){
                anc = 'A';
            } bi[i] == A bi[i] bi i A {
                anc = 'A';
            } anc = 'A' anc 'A' System.out.println(anc) System.out.println System.out System System.out anc String[] args args public class Main{
    public static void main(String[] args) {
        Scanner sc = new Scanner(System.in);
        char A = sc.next().charAt(0);
        char [] bi = new char[26];
        char [] sm = new char[26];
        char AA = 'A';
        char a = 'a';
        char anc = 'a';
        for(int i = 0;i < 26;i++){
            bi[i] = AA++;
            sm[i] = a++;
        }
        for(int i = 0;i < 26;i++){
            if(bi[i] == A){
                anc = 'A';
            }
        }
        System.out.println(anc);
    }
} public class Main{
    public static void main(String[] args) {
        Scanner sc = new Scanner(System.in);
        char A = sc.next().charAt(0);
        char [] bi = new char[26];
        char [] sm = new char[26];
        char AA = 'A';
        char a = 'a';
        char anc = 'a';
        for(int i = 0;i < 26;i++){
            bi[i] = AA++;
            sm[i] = a++;
        }
        for(int i = 0;i < 26;i++){
            if(bi[i] == A){
                anc = 'A';
            }
        }
        System.out.println(anc);
    }
} Main
import java.util.*;
public class Main{
    public static void main(String[] args) {
        Scanner sc = new Scanner(System.in);
        char A = sc.next().charAt(0);
        char [] bi = new char[26];
        char [] sm = new char[26];
        char AA = 'A';
        char a = 'a';
        char anc = 'a';
        for(int i = 0;i < 26;i++){
            bi[i] = AA++;
            sm[i] = a++;
        }
        for(int i = 0;i < 26;i++){
            if(bi[i] == A){
                anc = 'A';
            }
        }
        System.out.println(anc);
    }
}