import java.util.Scanner;

public class Main {

	public static int a = 0;

	public static void main(String[] args) {
		Scanner scan = new Scanner(System.in);
		String row = scan.next();
		if((row.equalsIgnoreCase("aaa"))||(row.equalsIgnoreCase("bbb"))) {
		    System.out.println("No");
		}
		else {
		    System.out.println("Yes");
		}
	}

} import java.util.Scanner; Scanner java.util public class Main {

	public static int a = 0;

	public static void main(String[] args) {
		Scanner scan = new Scanner(System.in);
		String row = scan.next();
		if((row.equalsIgnoreCase("aaa"))||(row.equalsIgnoreCase("bbb"))) {
		    System.out.println("No");
		}
		else {
		    System.out.println("Yes");
		}
	}

} Main public static int a = 0; a 0 public static void main(String[] args) {
		Scanner scan = new Scanner(System.in);
		String row = scan.next();
		if((row.equalsIgnoreCase("aaa"))||(row.equalsIgnoreCase("bbb"))) {
		    System.out.println("No");
		}
		else {
		    System.out.println("Yes");
		}
	} main {
		Scanner scan = new Scanner(System.in);
		String row = scan.next();
		if((row.equalsIgnoreCase("aaa"))||(row.equalsIgnoreCase("bbb"))) {
		    System.out.println("No");
		}
		else {
		    System.out.println("Yes");
		}
	} Scanner scan = new Scanner(System.in); scan new Scanner(System.in) String row = scan.next(); row scan.next() scan.next scan if((row.equalsIgnoreCase("aaa"))||(row.equalsIgnoreCase("bbb"))) {
		    System.out.println("No");
		}
		else {
		    System.out.println("Yes");
		} (row.equalsIgnoreCase("aaa"))||(row.equalsIgnoreCase("bbb")) (row.equalsIgnoreCase("aaa")) row.equalsIgnoreCase row "aaa" (row.equalsIgnoreCase("bbb")) row.equalsIgnoreCase row "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 int a = 0;

	public static void main(String[] args) {
		Scanner scan = new Scanner(System.in);
		String row = scan.next();
		if((row.equalsIgnoreCase("aaa"))||(row.equalsIgnoreCase("bbb"))) {
		    System.out.println("No");
		}
		else {
		    System.out.println("Yes");
		}
	}

} public class Main {

	public static int a = 0;

	public static void main(String[] args) {
		Scanner scan = new Scanner(System.in);
		String row = scan.next();
		if((row.equalsIgnoreCase("aaa"))||(row.equalsIgnoreCase("bbb"))) {
		    System.out.println("No");
		}
		else {
		    System.out.println("Yes");
		}
	}

} Main
import java.util.Scanner;

public class Main {

	public static int a = 0;

	public static void main(String[] args) {
		Scanner scan = new Scanner(System.in);
		String row = scan.next();
		if((row.equalsIgnoreCase("aaa"))||(row.equalsIgnoreCase("bbb"))) {
		    System.out.println("No");
		}
		else {
		    System.out.println("Yes");
		}
	}

}
