input: Write a function to implement a personalized mailing system.
  assert personalizedMailingSystem({"name": "Alice", "email": "alice@example.com", "topics": ["Data Science", "Python"]})==None
  assert personalizedMailingSystem({"name": "Bob", "email": "bob@example.com", "topics": ["Cybersecurity", "Blockchain"]})==None
  assert personalizedMailingSystem({"name": "Charlie", "email": "charlie@example.com", "topics": ["IoT", "Cloud Computing"]})==None
output: def personalizedMailingSystem(user_info):
      name = user_info["name"]
      email = user_info["email"]
      topics = user_info["topics"]
  
      print(f"Sending email to: {name} at {email}")
      print("Topics of interest:")
      for topic in topics:
          print(f" - {topic}")