import java.util.*;

// "static void main" must be defined in a public class.
public class Main {

    public static void main(String[] args) {
        Scanner sc = new Scanner(System.in);

        String input = sc.nextLine();
        boolean a = false;
        boolean b = false;
        for (char c : input.toCharArray()) {
            if (c == 'A') a = true;
            if (c == 'B') b = true;
        }

        if(a && 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