import java.util.*;
import java.util.Map.Entry;
 
class Main {
	 static int mod =  (int) (Math.pow(10,9)+7);
	 static int[] ans;
//	 static int mod = 998244353;
   public static void main(String[] args) {
	          
	   Scanner sc = new Scanner(System.in);
       String  N = sc.next();
       String ans;
       if(N.equals("AAA")||N.equals("BBB")) {
    	   ans="No";
       } else {
    	   ans="Yes";
       }
       System.out.println(ans); 
       return;
   }

} import java.util.*; util.* java import java.util.Map.Entry; Entry java.util.Map class Main {
	 static int mod =  (int) (Math.pow(10,9)+7);
	 static int[] ans;
//	 static int mod = 998244353;
   public static void main(String[] args) {
	          
	   Scanner sc = new Scanner(System.in);
       String  N = sc.next();
       String ans;
       if(N.equals("AAA")||N.equals("BBB")) {
    	   ans="No";
       } else {
    	   ans="Yes";
       }
       System.out.println(ans); 
       return;
   }

} Main static int mod =  (int) (Math.pow(10,9)+7); mod (int) (Math.pow(10,9)+7) Math.pow(10,9) Math.pow Math 10 9 7 static int[] ans; ans //	 static int mod = 998244353;
   public static void main(String[] args) {
	          
	   Scanner sc = new Scanner(System.in);
       String  N = sc.next();
       String ans;
       if(N.equals("AAA")||N.equals("BBB")) {
    	   ans="No";
       } else {
    	   ans="Yes";
       }
       System.out.println(ans); 
       return;
   } main {
	          
	   Scanner sc = new Scanner(System.in);
       String  N = sc.next();
       String ans;
       if(N.equals("AAA")||N.equals("BBB")) {
    	   ans="No";
       } else {
    	   ans="Yes";
       }
       System.out.println(ans); 
       return;
   } Scanner sc = new Scanner(System.in); sc new Scanner(System.in) String  N = sc.next(); N sc.next() sc.next sc String ans; ans if(N.equals("AAA")||N.equals("BBB")) {
    	   ans="No";
       } else {
    	   ans="Yes";
       } N.equals("AAA")||N.equals("BBB") N.equals("AAA") N.equals N "AAA" N.equals("BBB") N.equals N "BBB" {
    	   ans="No";
       } ans="No" ans "No" {
    	   ans="Yes";
       } ans="Yes" ans "Yes" System.out.println(ans) System.out.println System.out System System.out ans return; String[] args args
import java.util.*;
import java.util.Map.Entry;
 
class Main {
	 static int mod =  (int) (Math.pow(10,9)+7);
	 static int[] ans;
//	 static int mod = 998244353;
   public static void main(String[] args) {
	          
	   Scanner sc = new Scanner(System.in);
       String  N = sc.next();
       String ans;
       if(N.equals("AAA")||N.equals("BBB")) {
    	   ans="No";
       } else {
    	   ans="Yes";
       }
       System.out.println(ans); 
       return;
   }

}