import java.util.Scanner;
public class Main {
	public static void main(String[] args){
		Scanner as = new Scanner(System.in);
		//int n = Integer.parseInt(as.next());
		String st = as.next();
      if(st.equals("AAA") || st.equals("BBB")){
		System.out.println("No");
      }else{System.out.println("Yes");
      }
	}
} import java.util.Scanner; Scanner java.util public class Main {
	public static void main(String[] args){
		Scanner as = new Scanner(System.in);
		//int n = Integer.parseInt(as.next());
		String st = as.next();
      if(st.equals("AAA") || st.equals("BBB")){
		System.out.println("No");
      }else{System.out.println("Yes");
      }
	}
} Main public static void main(String[] args){
		Scanner as = new Scanner(System.in);
		//int n = Integer.parseInt(as.next());
		String st = as.next();
      if(st.equals("AAA") || st.equals("BBB")){
		System.out.println("No");
      }else{System.out.println("Yes");
      }
	} main {
		Scanner as = new Scanner(System.in);
		//int n = Integer.parseInt(as.next());
		String st = as.next();
      if(st.equals("AAA") || st.equals("BBB")){
		System.out.println("No");
      }else{System.out.println("Yes");
      }
	} Scanner as = new Scanner(System.in); as new Scanner(System.in) String st = as.next(); st as.next() as.next as if(st.equals("AAA") || st.equals("BBB")){
		System.out.println("No");
      }else{System.out.println("Yes");
      } st.equals("AAA") || st.equals("BBB") st.equals("AAA") st.equals st "AAA" st.equals("BBB") st.equals st "BBB" {
		System.out.println("No");
      } System.out.println("No") System.out.println System.out System System.out "No" {System.out.println("Yes");
      } System.out.println("Yes") System.out.println System.out System System.out "Yes" String[] args args public class Main {
	public static void main(String[] args){
		Scanner as = new Scanner(System.in);
		//int n = Integer.parseInt(as.next());
		String st = as.next();
      if(st.equals("AAA") || st.equals("BBB")){
		System.out.println("No");
      }else{System.out.println("Yes");
      }
	}
} public class Main {
	public static void main(String[] args){
		Scanner as = new Scanner(System.in);
		//int n = Integer.parseInt(as.next());
		String st = as.next();
      if(st.equals("AAA") || st.equals("BBB")){
		System.out.println("No");
      }else{System.out.println("Yes");
      }
	}
} Main
import java.util.Scanner;
public class Main {
	public static void main(String[] args){
		Scanner as = new Scanner(System.in);
		//int n = Integer.parseInt(as.next());
		String st = as.next();
      if(st.equals("AAA") || st.equals("BBB")){
		System.out.println("No");
      }else{System.out.println("Yes");
      }
	}
}