import java.util.Scanner;

 
public class Main {
 
	public static void main(String[] args) {
		
		Scanner sc = new Scanner(System.in);
		String S = sc.nextLine();
		
		if(S.equals("AAA") || S.equals("BBB")) {
			System.out.print("No");
		}else {
			System.out.print("Yes");
		}
		sc.close();
	}
	
} import java.util.Scanner; Scanner java.util public class Main {
 
	public static void main(String[] args) {
		
		Scanner sc = new Scanner(System.in);
		String S = sc.nextLine();
		
		if(S.equals("AAA") || S.equals("BBB")) {
			System.out.print("No");
		}else {
			System.out.print("Yes");
		}
		sc.close();
	}
	
} Main public static void main(String[] args) {
		
		Scanner sc = new Scanner(System.in);
		String S = sc.nextLine();
		
		if(S.equals("AAA") || S.equals("BBB")) {
			System.out.print("No");
		}else {
			System.out.print("Yes");
		}
		sc.close();
	} main {
		
		Scanner sc = new Scanner(System.in);
		String S = sc.nextLine();
		
		if(S.equals("AAA") || S.equals("BBB")) {
			System.out.print("No");
		}else {
			System.out.print("Yes");
		}
		sc.close();
	} Scanner sc = new Scanner(System.in); sc new Scanner(System.in) String S = sc.nextLine(); S sc.nextLine() sc.nextLine sc if(S.equals("AAA") || S.equals("BBB")) {
			System.out.print("No");
		}else {
			System.out.print("Yes");
		} S.equals("AAA") || S.equals("BBB") S.equals("AAA") S.equals S "AAA" S.equals("BBB") S.equals S "BBB" {
			System.out.print("No");
		} System.out.print("No") System.out.print System.out System System.out "No" {
			System.out.print("Yes");
		} System.out.print("Yes") System.out.print System.out System System.out "Yes" sc.close() sc.close sc String[] args args public class Main {
 
	public static void main(String[] args) {
		
		Scanner sc = new Scanner(System.in);
		String S = sc.nextLine();
		
		if(S.equals("AAA") || S.equals("BBB")) {
			System.out.print("No");
		}else {
			System.out.print("Yes");
		}
		sc.close();
	}
	
} public class Main {
 
	public static void main(String[] args) {
		
		Scanner sc = new Scanner(System.in);
		String S = sc.nextLine();
		
		if(S.equals("AAA") || S.equals("BBB")) {
			System.out.print("No");
		}else {
			System.out.print("Yes");
		}
		sc.close();
	}
	
} Main
import java.util.Scanner;

 
public class Main {
 
	public static void main(String[] args) {
		
		Scanner sc = new Scanner(System.in);
		String S = sc.nextLine();
		
		if(S.equals("AAA") || S.equals("BBB")) {
			System.out.print("No");
		}else {
			System.out.print("Yes");
		}
		sc.close();
	}
	
}