import java.util.*;
import java.lang.*;
public class Main {
    public static void main(String args[]) {
      Scanner sc = new Scanner(System.in);
     String str=sc.nextLine();
     String s1=str.substring(0);
      char c1=str.charAt(0);
      char c2=str.charAt(1);
      char c3= str.charAt(2);
     
      if(c1==c2 && c2==c3)
      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