import java.util.*;

public class Main {

  public static void main(String[] args) {

    Scanner sc = new Scanner(System.in);
    String s = sc.next();
    char c[] = s.toCharArray();

    if (c[0] == c[1] && c[1] == c[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