import java.util.Scanner;


public class Main {

	/**
	 * @param args
	 */
	public static void main(String[] args) {
		// TODO Auto-generated method stub
Scanner sc =new Scanner(System.in);
String s =sc.next();
boolean b =true;
if(s.charAt(0)==s.charAt(1)&&s.charAt(1)==s.charAt(2)){
	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