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