import java.io.BufferedReader;
import java.io.*;
import java.util.*;
import java.util.ArrayList;
import java.util.Iterator;
import java.util.List;
import java.util.Collections;
public class Main {
	public static void main(final String[] args){
        Scanner sc = new Scanner(System.in);
        String s = sc.next();

        if(s.equals("AAA") || s.equals("BBB")){
            System.out.println("No");
        }else{
            System.out.println("Yes");
        }


        
	}
} import java.io.BufferedReader; BufferedReader java.io import java.io.*; io.* java import java.util.*; util.* java import java.util.ArrayList; ArrayList java.util import java.util.Iterator; Iterator java.util import java.util.List; List java.util import java.util.Collections; Collections java.util public class Main {
	public static void main(final String[] args){
        Scanner sc = new Scanner(System.in);
        String s = sc.next();

        if(s.equals("AAA") || s.equals("BBB")){
            System.out.println("No");
        }else{
            System.out.println("Yes");
        }


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

        if(s.equals("AAA") || s.equals("BBB")){
            System.out.println("No");
        }else{
            System.out.println("Yes");
        }


        
	} main {
        Scanner sc = new Scanner(System.in);
        String s = sc.next();

        if(s.equals("AAA") || s.equals("BBB")){
            System.out.println("No");
        }else{
            System.out.println("Yes");
        }


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

        if(s.equals("AAA") || s.equals("BBB")){
            System.out.println("No");
        }else{
            System.out.println("Yes");
        }


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

        if(s.equals("AAA") || s.equals("BBB")){
            System.out.println("No");
        }else{
            System.out.println("Yes");
        }


        
	}
} Main
import java.io.BufferedReader;
import java.io.*;
import java.util.*;
import java.util.ArrayList;
import java.util.Iterator;
import java.util.List;
import java.util.Collections;
public class Main {
	public static void main(final String[] args){
        Scanner sc = new Scanner(System.in);
        String s = sc.next();

        if(s.equals("AAA") || s.equals("BBB")){
            System.out.println("No");
        }else{
            System.out.println("Yes");
        }


        
	}
}