import java.util.Scanner;

class Main{

    public static void main(String[] args){

        Scanner scanner = new Scanner(System.in);
        String input = scanner.next();
        scanner.close();
        char[] chr = {input.charAt(0), input.charAt(1), input.charAt(2)};
        if(chr[0]!=chr[1] || chr[0]!=chr[2] || chr[1]!=chr[2]){
            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