import java.awt.Event;
import java.awt.geom.Point2D;
import java.io.BufferedReader;
import java.io.BufferedWriter;
import java.io.File;
import java.io.FileInputStream;
import java.io.FileNotFoundException;
import java.io.FileOutputStream;
import java.io.FileReader;
import java.io.FileWriter;
import java.io.IOException;
import java.io.PrintWriter;
import java.nio.channels.FileChannel;
import java.sql.Timestamp;
import java.text.SimpleDateFormat;
import java.util.ArrayList;
import java.util.Collection;
import java.util.Collections;
import java.util.Comparator;
import java.util.HashMap;
import java.util.Scanner;
import java.util.TreeSet;
import java.util.regex.Matcher;
import java.util.regex.Pattern;
import java.util.stream.IntStream;

public class Main {
	Scanner sc = new Scanner(System.in);
	public static void main(String[] args){
		new Main();
	}
	public Main(){
		new TestA().doIt();
	}
	class TestA{
		void doIt() {
			String str = sc.next();
			if(str.equals("AAA") || str.equals("BBB")) {
				System.out.println("No");
			}else {
				System.out.println("Yes");
			}
		}
	}
} import java.awt.Event; Event java.awt import java.awt.geom.Point2D; Point2D java.awt.geom import java.io.BufferedReader; BufferedReader java.io import java.io.BufferedWriter; BufferedWriter java.io import java.io.File; File java.io import java.io.FileInputStream; FileInputStream java.io import java.io.FileNotFoundException; FileNotFoundException java.io import java.io.FileOutputStream; FileOutputStream java.io import java.io.FileReader; FileReader java.io import java.io.FileWriter; FileWriter java.io import java.io.IOException; IOException java.io import java.io.PrintWriter; PrintWriter java.io import java.nio.channels.FileChannel; FileChannel java.nio.channels import java.sql.Timestamp; Timestamp java.sql import java.text.SimpleDateFormat; SimpleDateFormat java.text import java.util.ArrayList; ArrayList java.util import java.util.Collection; Collection java.util import java.util.Collections; Collections java.util import java.util.Comparator; Comparator java.util import java.util.HashMap; HashMap java.util import java.util.Scanner; Scanner java.util import java.util.TreeSet; TreeSet java.util import java.util.regex.Matcher; Matcher java.util.regex import java.util.regex.Pattern; Pattern java.util.regex import java.util.stream.IntStream; IntStream java.util.stream public class Main {
	Scanner sc = new Scanner(System.in);
	public static void main(String[] args){
		new Main();
	}
	public Main(){
		new TestA().doIt();
	}
	class TestA{
		void doIt() {
			String str = sc.next();
			if(str.equals("AAA") || str.equals("BBB")) {
				System.out.println("No");
			}else {
				System.out.println("Yes");
			}
		}
	}
} Main Scanner sc = new Scanner(System.in); sc new Scanner(System.in) public static void main(String[] args){
		new Main();
	} main {
		new Main();
	} new Main() String[] args args public Main(){
		new TestA().doIt();
	} Main {
		new TestA().doIt();
	} new TestA().doIt() new TestA().doIt new TestA() class TestA{
		void doIt() {
			String str = sc.next();
			if(str.equals("AAA") || str.equals("BBB")) {
				System.out.println("No");
			}else {
				System.out.println("Yes");
			}
		}
	} TestA void doIt() {
			String str = sc.next();
			if(str.equals("AAA") || str.equals("BBB")) {
				System.out.println("No");
			}else {
				System.out.println("Yes");
			}
		} doIt {
			String str = sc.next();
			if(str.equals("AAA") || str.equals("BBB")) {
				System.out.println("No");
			}else {
				System.out.println("Yes");
			}
		} String str = sc.next(); str sc.next() sc.next sc if(str.equals("AAA") || str.equals("BBB")) {
				System.out.println("No");
			}else {
				System.out.println("Yes");
			} str.equals("AAA") || str.equals("BBB") str.equals("AAA") str.equals str "AAA" str.equals("BBB") str.equals str "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" public class Main {
	Scanner sc = new Scanner(System.in);
	public static void main(String[] args){
		new Main();
	}
	public Main(){
		new TestA().doIt();
	}
	class TestA{
		void doIt() {
			String str = sc.next();
			if(str.equals("AAA") || str.equals("BBB")) {
				System.out.println("No");
			}else {
				System.out.println("Yes");
			}
		}
	}
} public class Main {
	Scanner sc = new Scanner(System.in);
	public static void main(String[] args){
		new Main();
	}
	public Main(){
		new TestA().doIt();
	}
	class TestA{
		void doIt() {
			String str = sc.next();
			if(str.equals("AAA") || str.equals("BBB")) {
				System.out.println("No");
			}else {
				System.out.println("Yes");
			}
		}
	}
} Main
import java.awt.Event;
import java.awt.geom.Point2D;
import java.io.BufferedReader;
import java.io.BufferedWriter;
import java.io.File;
import java.io.FileInputStream;
import java.io.FileNotFoundException;
import java.io.FileOutputStream;
import java.io.FileReader;
import java.io.FileWriter;
import java.io.IOException;
import java.io.PrintWriter;
import java.nio.channels.FileChannel;
import java.sql.Timestamp;
import java.text.SimpleDateFormat;
import java.util.ArrayList;
import java.util.Collection;
import java.util.Collections;
import java.util.Comparator;
import java.util.HashMap;
import java.util.Scanner;
import java.util.TreeSet;
import java.util.regex.Matcher;
import java.util.regex.Pattern;
import java.util.stream.IntStream;

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