import java.util.*;

public class Main {
    public static void main(String[] args) throws Exception {
        Scanner sn = new Scanner(System.in);
        
        String s = sn.nextLine();
        
        if((s.substring(0,1)).equals(s.substring(1,2))
            && (s.substring(1,2)).equals(s.substring(2,3))) {
              System.out.print("No");  
              return;
        }
        
        System.out.print("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