import java.io.*;
import java.util.*;

public class Main {
    static Character[] toCharacterArray(String s) {
        if (s == null) {
            return null;
        }
        int len = s.length();
        Character[] array = new Character[len];
        for (int i = 0; i < len; i++) {
            array[i] = new Character(s.charAt(i));
        }
        return array;
    }

    public static void main(String[] args) throws Exception {
        BufferedReader reader = new BufferedReader(new InputStreamReader(System.in));
        String arr = reader.readLine();

        Set<Character> S = new HashSet<Character>(Arrays.asList(toCharacterArray(arr)));
        System.out.println(1 < S.size() ? "Yes" : "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