import java.util.*;
import java.util.Scanner;
class Main{
    public static void main(String[] args)
    {
        String n;
        char station = ' ';
        int result = 0;
        Scanner scanner = new Scanner(System.in);
        n = scanner.next();

        for(int i = 0; i < n.length(); i++){
            if(i == 0){
                station = n.charAt(i); 
            }else if(station != n.charAt(i)){
                result = 1;
                break;
            }
        }
        if(result == 1){
            System.out.println("Yes");
        }else{
            System.out.println("No");
        }
    }
}
/tmp/hf-datasets-cache/medium/datasets/42704881117311-config-parquet-and-info-qiankunmu-Project_CodeNet-896c9d36/hub/datasets--qiankunmu--Project_CodeNet_Python800_and_Java250/snapshots/c899fde44a77ba1cc14973ed3de064e4ff3aadc7/Project_CodeNet_Java250.tar.gz