import java.io.*;
import java.util.*;

class Main{
    public static void main(String[] args)throws IOException{
      try(BufferedReader br = new BufferedReader(new InputStreamReader(System.in))){
        String input = br.readLine();
        int result = 0;

        if(input.contains("A")){
          result++;
        }

        if(input.contains("B")){
          result++;
        }

        if(result == 2){
          System.out.println("Yes");
        }else{
          System.out.println("No");
        }
      }
    }
}
/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