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