import java.util.*;

public class Main{
  
  public static void main (String []args){
    Scanner sc = new Scanner(System.in);
    String s = sc.next();
    int a = 0;
    int b = 0;
    
    for (int i = 0; i <= 2; i++){
      if (s.charAt(i) == 'A'){
        a++;
      }else {
        b++;
      }
    }
    if (a == 3 || b ==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