import java.util.Scanner;

class Main {
	public static void main(String[] args) {
		Scanner sc = new Scanner(System.in);
		String S = sc.next();
		boolean yes = true;
		if(S.equals("AAA") || S.equals("BBB")) yes = false;
		if(yes) {
			System.out.println("Yes");
		}else {
			System.out.println("No");
		}
		
	}
}

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

class Main {
	public static void main(String[] args) {
		Scanner sc = new Scanner(System.in);
		String S = sc.next();
		boolean yes = true;
		if(S.equals("AAA") || S.equals("BBB")) yes = false;
		if(yes) {
			System.out.println("Yes");
		}else {
			System.out.println("No");
		}
		
	}
}


