import java.util.Scanner;
 
public class Main {
	public static void main(String[] args) {
      Scanner sc = new Scanner(System.in);
      String S = sc.next();
      
      
      String S1 = "AAA";
      String S2 = "BBB";
      
      if(S.equals(S1)){
      System.out.println("No");
      }
      else if(S.equals(S2)){
      System.out.println("No");
      }
      else{
        System.out.println("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