import java.util.*;

public class Main{
  public static void main(String[] args) {
    Scanner sc=new Scanner(System.in);
    String s=sc.next();
    if (s.charAt(0)=='A'&&s.charAt(1)=='A'&&s.charAt(2)=='A'||s.charAt(0)=='B'&&s.charAt(1)=='B'&&s.charAt(2)=='B') {
      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