import java.util.*;
import java.lang.Math;

public class Main {
	public static void main(String[] args){
		Scanner sc = new Scanner(System.in);

  		
      	String sta = sc.next();
      	String str = "Yes";
      	
      	if(sta.equals("AAA") || sta.equals("BBB")) str = "No";
      	
      	
      	System.out.println(str);
        
	}
} import java.util.*; util.* java import java.lang.Math; Math java.lang public class Main {
	public static void main(String[] args){
		Scanner sc = new Scanner(System.in);

  		
      	String sta = sc.next();
      	String str = "Yes";
      	
      	if(sta.equals("AAA") || sta.equals("BBB")) str = "No";
      	
      	
      	System.out.println(str);
        
	}
} Main public static void main(String[] args){
		Scanner sc = new Scanner(System.in);

  		
      	String sta = sc.next();
      	String str = "Yes";
      	
      	if(sta.equals("AAA") || sta.equals("BBB")) str = "No";
      	
      	
      	System.out.println(str);
        
	} main {
		Scanner sc = new Scanner(System.in);

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

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

  		
      	String sta = sc.next();
      	String str = "Yes";
      	
      	if(sta.equals("AAA") || sta.equals("BBB")) str = "No";
      	
      	
      	System.out.println(str);
        
	}
} Main
import java.util.*;
import java.lang.Math;

public class Main {
	public static void main(String[] args){
		Scanner sc = new Scanner(System.in);

  		
      	String sta = sc.next();
      	String str = "Yes";
      	
      	if(sta.equals("AAA") || sta.equals("BBB")) str = "No";
      	
      	
      	System.out.println(str);
        
	}
}
