import java.util.*;

public class Main {
  public static void main(String[] args){
    Scanner sc = new Scanner(System.in);
    String str = sc.next();
    //int N = sc.nextInt();
    int count = 0;
    
    if(str.charAt(0) == str.charAt(1)){
        count++;
    }else{
    }
    if(str.charAt(0) == str.charAt(2)){
        count++;
    }else{
    }
    if(str.charAt(1) == str.charAt(2)){
        count++;
    }else{
    }
    
    if(count == 3){
        System.out.println("No");
    }else{
        System.out.println("Yes");
    }
  }
}
/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