import java.util.*;

public class Main {
    public static void main(String[] args) throws Exception {
        Scanner sn = new Scanner(System.in);
        
        String s = sn.nextLine();
        
        if((s.substring(0,1)).equals(s.substring(1,2))
            && (s.substring(1,2)).equals(s.substring(2,3))) {
              System.out.print("No");  
              return;
        }
        
        System.out.print("Yes");
    }
} import java.util.*; util.* java public class Main {
    public static void main(String[] args) throws Exception {
        Scanner sn = new Scanner(System.in);
        
        String s = sn.nextLine();
        
        if((s.substring(0,1)).equals(s.substring(1,2))
            && (s.substring(1,2)).equals(s.substring(2,3))) {
              System.out.print("No");  
              return;
        }
        
        System.out.print("Yes");
    }
} Main public static void main(String[] args) throws Exception {
        Scanner sn = new Scanner(System.in);
        
        String s = sn.nextLine();
        
        if((s.substring(0,1)).equals(s.substring(1,2))
            && (s.substring(1,2)).equals(s.substring(2,3))) {
              System.out.print("No");  
              return;
        }
        
        System.out.print("Yes");
    } main {
        Scanner sn = new Scanner(System.in);
        
        String s = sn.nextLine();
        
        if((s.substring(0,1)).equals(s.substring(1,2))
            && (s.substring(1,2)).equals(s.substring(2,3))) {
              System.out.print("No");  
              return;
        }
        
        System.out.print("Yes");
    } Scanner sn = new Scanner(System.in); sn new Scanner(System.in) String s = sn.nextLine(); s sn.nextLine() sn.nextLine sn if((s.substring(0,1)).equals(s.substring(1,2))
            && (s.substring(1,2)).equals(s.substring(2,3))) {
              System.out.print("No");  
              return;
        } (s.substring(0,1)).equals(s.substring(1,2))
            && (s.substring(1,2)).equals(s.substring(2,3)) (s.substring(0,1)).equals(s.substring(1,2)) (s.substring(0,1)).equals (s.substring(0,1)) s.substring s 0 1 s.substring(1,2) s.substring s 1 2 (s.substring(1,2)).equals(s.substring(2,3)) (s.substring(1,2)).equals (s.substring(1,2)) s.substring s 1 2 s.substring(2,3) s.substring s 2 3 {
              System.out.print("No");  
              return;
        } System.out.print("No") System.out.print System.out System System.out "No" return; System.out.print("Yes") System.out.print System.out System System.out "Yes" String[] args args public class Main {
    public static void main(String[] args) throws Exception {
        Scanner sn = new Scanner(System.in);
        
        String s = sn.nextLine();
        
        if((s.substring(0,1)).equals(s.substring(1,2))
            && (s.substring(1,2)).equals(s.substring(2,3))) {
              System.out.print("No");  
              return;
        }
        
        System.out.print("Yes");
    }
} public class Main {
    public static void main(String[] args) throws Exception {
        Scanner sn = new Scanner(System.in);
        
        String s = sn.nextLine();
        
        if((s.substring(0,1)).equals(s.substring(1,2))
            && (s.substring(1,2)).equals(s.substring(2,3))) {
              System.out.print("No");  
              return;
        }
        
        System.out.print("Yes");
    }
} Main
import java.util.*;

public class Main {
    public static void main(String[] args) throws Exception {
        Scanner sn = new Scanner(System.in);
        
        String s = sn.nextLine();
        
        if((s.substring(0,1)).equals(s.substring(1,2))
            && (s.substring(1,2)).equals(s.substring(2,3))) {
              System.out.print("No");  
              return;
        }
        
        System.out.print("Yes");
    }
}
