import java.util.*;
import java.lang.*;
public class Main{
    public static void main(String args[]){
        str ans=new str();
        ans.sp();
    }
}
class str{
    String s;
    void sp(){
        Scanner sc=new Scanner(System.in);
        s=sc.nextLine();
        if(s.contains("A")&&s.contains("B")){
            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