import java.util.*;

public class Main{
  public static void main(String[] args){
    Scanner sc = new Scanner(System.in);
    String str = sc.next();
    if(str.equals("AAA") || str.equals("BBB") || str.length() != 3){
      System.out.println("No");
    } else {
      System.out.println("Yes");
    }
  }
} import java.util.*; util.* java public class Main{
  public static void main(String[] args){
    Scanner sc = new Scanner(System.in);
    String str = sc.next();
    if(str.equals("AAA") || str.equals("BBB") || str.length() != 3){
      System.out.println("No");
    } else {
      System.out.println("Yes");
    }
  }
} Main public static void main(String[] args){
    Scanner sc = new Scanner(System.in);
    String str = sc.next();
    if(str.equals("AAA") || str.equals("BBB") || str.length() != 3){
      System.out.println("No");
    } else {
      System.out.println("Yes");
    }
  } main {
    Scanner sc = new Scanner(System.in);
    String str = sc.next();
    if(str.equals("AAA") || str.equals("BBB") || str.length() != 3){
      System.out.println("No");
    } else {
      System.out.println("Yes");
    }
  } Scanner sc = new Scanner(System.in); sc new Scanner(System.in) String str = sc.next(); str sc.next() sc.next sc if(str.equals("AAA") || str.equals("BBB") || str.length() != 3){
      System.out.println("No");
    } else {
      System.out.println("Yes");
    } str.equals("AAA") || str.equals("BBB") || str.length() != 3 str.equals("AAA") || str.equals("BBB") || str.length() != 3 str.equals("AAA") str.equals str "AAA" str.equals("BBB") str.equals str "BBB" str.length() != 3 str.length() str.length str 3 {
      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 sc = new Scanner(System.in);
    String str = sc.next();
    if(str.equals("AAA") || str.equals("BBB") || str.length() != 3){
      System.out.println("No");
    } else {
      System.out.println("Yes");
    }
  }
} public class Main{
  public static void main(String[] args){
    Scanner sc = new Scanner(System.in);
    String str = sc.next();
    if(str.equals("AAA") || str.equals("BBB") || str.length() != 3){
      System.out.println("No");
    } else {
      System.out.println("Yes");
    }
  }
} Main
import java.util.*;

public class Main{
  public static void main(String[] args){
    Scanner sc = new Scanner(System.in);
    String str = sc.next();
    if(str.equals("AAA") || str.equals("BBB") || str.length() != 3){
      System.out.println("No");
    } else {
      System.out.println("Yes");
    }
  }
}
