import java.util.*;
class Main
{
    public static void main(String[] args)
    {
        Scanner sc = new Scanner(System.in);
        
        String s = sc.next();
        
        String a = s.substring(0,1);
        String b = s.substring(1,2);
        String c = s.substring(2,3);
        
        if((a.equals(b))&&(a.equals(c))){
            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