    import java.util.*;
     
    public class Main {
      public static void main(String[] args) {
        Scanner sc = new Scanner(System.in); 
        String S = sc.next();
        boolean key = false;
        if (S.equals("AAA") || S.equals("BBB")) key = true;
        else ;
        System.out.println(key ? "No" : "Yes");
      }
    }
/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