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);
    }
}
/tmp/hf-datasets-cache/medium/datasets/42704881117311-config-parquet-and-info-qiankunmu-Project_CodeNet-896c9d36/hub/datasets--qiankunmu--Project_CodeNet_Python800_and_Java250/snapshots/c899fde44a77ba1cc14973ed3de064e4ff3aadc7/Project_CodeNet_Java250.tar.gz