import java.util.*;
public class Main{
  public static void main(String[] args){
    Scanner sc = new Scanner(System.in);
    char S = sc.next().charAt(0);
    if(S=='A' ){
      System.out.println("A");
      return;
    }
    if(S=='B' ){
      System.out.println("A");
      return;

    }
    if(S=='C' ){
      System.out.println("A");
      return;
    }
    if(S=='D' ){
      System.out.println("A");
      return;
    }
    if(S=='E' ){
      System.out.println("A");
      return;
    }
    if(S=='F' ){
      System.out.println("A");
      return;
    }
    if(S=='G' ){
      System.out.println("A");
      return;
    }
    if(S=='H' ){
      System.out.println("A");
      return;
    }
    if(S=='I' ){
      System.out.println("A");
      return;
    }
    if(S=='J' ){
      System.out.println("A");
      return;
    }
    if(S=='K' ){
      System.out.println("A");
      return;
    }
    if(S=='L' ){
      System.out.println("A");
      return;
    }
    if(S=='M' ){
      System.out.println("A");
      return;
    }    
    if(S=='N' ){
      System.out.println("A");
      return;
    }
    if(S=='O' ){
      System.out.println("A");
      return;
    }
    if(S=='P' ){
      System.out.println("A");
      return;
    }
    if(S=='Q' ){
      System.out.println("A");
      return;
    }
    if(S=='R' ){
      System.out.println("A");
      return;
    }
    if(S=='S' ){
      System.out.println("A");
      return;
    }
    if(S=='T' ){
      System.out.println("A");
      return;
    }
    if(S=='U' ){
      System.out.println("A");
      return;
    }
    if(S=='V' ){
      System.out.println("A");
      return;
    }
    if(S=='W' ){
      System.out.println("A");
      return;
    }
    if(S=='X' ){
      System.out.println("A");
      return;
    }
    if(S=='Y' ){
      System.out.println("A");
      return;
    }
    if(S=='Z' ){
      System.out.println("A");
      return;
    }
    
    System.out.println("a");


  }
  
}


/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