user: You are a structured reasoning expert tasked with solving problems step by step. 
You first think about the reasoning process in the mind and then provide the answer. The reasoning process and answer should be enclosed within <think> </think> and <answer> </answer> tags, respectively, i.e., <think> reasoning process here </think> <answer> answer here </answer>. 
Given a question and the associated knowledge graph triplets (entity, relation, entity), you are asked to answer the question with these triplets and your own knowledge. 
You can break down the original question into several sub-questions and explore the given knowledge graph to solve them step-by-step. If there are multiple possible answers, choose one as the final answer. 
After thinking, when you finally reach a conclusion, clearly state the answer within <answer> </answer> tags, i.e., <answer> answer here </answer>. 
Question: What illness did the actor who played the character Della Chappell have? 
Knowledge Triplets: Mysophobia, medicine.disease.symptoms, Avoiding people, places or things in order to prevent germ contamination
Fictional Character, freebase.type_profile.published, Published
Joan Crawford, medicine.notable_person_with_medical_condition.condition, Mysophobia
Mysophobia, base.phobias.phobia.also_caused_by_medical_condition, Obsessive-compulsive disorder
Nikola Tesla, medicine.notable_person_with_medical_condition.condition, Mysophobia
Joan Crawford, film.actor.film, m.0115tf9q
Topic, freebase.type_profile.kind, Portrayal
m.0115tf9q, film.performance.film, Della
Mysophobia, medicine.disease.notable_people_with_this_condition, Howard Hughes
Film character, freebase.type_profile.published, Published
Della Chappell, film.film_character.portrayed_in_films, m.0115tf9q
Fictional Character, freebase.type_profile.strict_included_types, Topic
Film character, freebase.type_hints.included_types, Topic
Mysophobia, medicine.disease.notable_people_with_this_condition, Woody Allen
Obsessive-compulsive disorder, medicine.disease.includes_diseases, Mysophobia
Leland Blaine Chapman, medicine.notable_person_with_medical_condition.condition, Mysophobia
Della, film.film.produced_by, Joan Crawford
Film character, type.type.properties, Portrayed in films (dubbed)
If fear takes over and one finds themselves suffering from physical symptoms, medicine.symptom.symptom_of, Mysophobia
Character, owl#inverseOf, Portrayed in films
Kerry King, medicine.notable_person_with_medical_condition.condition, Mysophobia
Mysophobia, base.phobias.phobia.fear_of, Germs
Film character, freebase.type_profile.kind, Portrayal
Della Chappell, common.topic.notable_for, g.11b5pgw4st
Cameron Diaz, medicine.notable_person_with_medical_condition.condition, Mysophobia
Joan Crawford, film.producer.film, Della
Film character, freebase.type_profile.strict_included_types, Topic
m.0115tf9q, film.performance.actor, Joan Crawford
mysophobia.noun.01, base.wordnet.synset.equivalent_topic, Mysophobia
m.0115tf9q, film.performance.actor, Joan Crawford
Mysophobia, medicine.disease.notable_people_with_this_condition, Kerry King
Film character, type.type.expected_by, Character
Phobia has persisted over a significant length of time and is affecting one’s health, mood, work or family life, medicine.symptom.symptom_of, Mysophobia
Della, film.film.starring, m.0115tf9q
Character, type.property.expected_type, Film character
Film character, type.type.domain, Film
One recognizes that avoiding germs is taking over daily routines, medicine.symptom.symptom_of, Mysophobia
Mysophobia, base.schemastaging.context_name.pronunciation, g.125_m6ds3
Film character, freebase.type_hints.included_types, Fictional Character
Film character, freebase.type_profile.strict_included_types, Fictional Character
Mysophobia, medicine.disease.symptoms, Phobia has persisted over a significant length of time and is affecting one’s health, mood, work or family life
Della Chappell, film.film_character.portrayed_in_films, m.0115tf9q
Film character, common.topic.article, m.02_96_z
Howie Mandel, medicine.notable_person_with_medical_condition.condition, Mysophobia
Film character, type.type.expected_by, Other conquests
Film character, freebase.type_profile.kind, Annotation
Della Chappell, common.topic.notable_types, Film character
Michael Jackson, medicine.notable_person_with_medical_condition.condition, Mysophobia
Film, type.domain.types, Film character
Woody Allen, medicine.notable_person_with_medical_condition.condition, Mysophobia
Mysophobia, medicine.disease.symptoms, If fear takes over and one finds themselves suffering from physical symptoms
Mysophobia, medicine.disease.notable_people_with_this_condition, Leland Blaine Chapman
Mysophobia, medicine.disease.parent_disease, Obsessive-compulsive disorder
Mysophobia, medicine.disease.notable_people_with_this_condition, Michael Jackson
Mysophobia, medicine.disease.notable_people_with_this_condition, Nikola Tesla
Joan Crawford, medicine.notable_person_with_medical_condition.condition, Mysophobia
m.0115tf9q, film.performance.character, Della Chappell
Fictional Character, freebase.type_hints.included_types, Topic
Mysophobia, medicine.disease.notable_people_with_this_condition, Howie Mandel
Film character, type.type.properties, Portrayed in films
Mysophobia, medicine.disease.symptoms, One recognizes that avoiding germs is taking over daily routines
Topic, freebase.type_profile.published, Published
Character, type.property.reverse_property, Portrayed in films
Mysophobia, medicine.disease.notable_people_with_this_condition, Joan Crawford
Avoiding people, places or things in order to prevent germ contamination, medicine.symptom.symptom_of, Mysophobia
Character, rdf-schema#range, Film character
Howard Hughes, medicine.notable_person_with_medical_condition.condition, Mysophobia
Film character, type.type.expected_by, Character using Wham-O product
Mysophobia, medicine.disease.notable_people_with_this_condition, Cameron Diaz
Film character, type.type.expected_by, Killed by
Fictional Character, freebase.type_profile.kind, Portrayal

Answer: Mysophobia