import java.util.Scanner;
public class Main {
	public static void main(String[] args) {
    	Scanner input = new Scanner(System.in);
      	String s = input.nextLine();
      	int c = 0;
        for (int i = 0; i < s.length(); i++)
        	if (s.charAt(i) == 'A')
              c++;
      	if (c == 0 || c == 3)
          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