import java.util.*;
public class Main  {
   public static void main(String[] args) throws java.lang.Exception  {
      Scanner sc = new Scanner(System.in);
      
      String  a = sc.next();
         
      char aa = a.charAt(0);
      char bb = a.charAt(1);
      char cc = a.charAt(2);
         
      if (aa == bb && bb == cc) {
         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