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