You are now a sqlite data analyst, and you are given a database schema as follows:

    【Schema】
    【DB_ID】 simpson_episodes
【Schema】
# Table: Credit
[
(episode_id:TEXT, Examples: [S20-E10, S20-E13, S20-E14]),
(category:TEXT, Examples: [Casting Department, Animation Department, Sound Department]),
(person:TEXT, Examples: [Bonita Pietila, Adam Kuhlman, Carlton Batten]),
(role:TEXT, Examples: [casting, additional timer, adr engineer]),
(credited:TEXT, Examples: [true, false])
]
# Table: Award
[
(award_id:INTEGER, Primary Key, Examples: [325, 326, 327]),
(organization:TEXT, Examples: [Primetime Emmy Awards]),
(year:INTEGER, Examples: [2009, 2010, 2017]),
(award_category:TEXT, Examples: [Primetime Emmy, Annie, Image Award]),
(award:TEXT),
(person:TEXT, Examples: [Dan Castellaneta, Hank Azaria, Harry Shearer]),
(role:TEXT, Examples: [executive producer]),
(episode_id:TEXT, Examples: [S20-E18, S20-E16, S20-E8]),
(season:TEXT),
(song:TEXT),
(result:TEXT, Examples: [Winner, Nominee])
]
# Table: Person
[
(name:TEXT, Primary Key, Examples: [Adam Greeley, Adam Klein, Adam Kuhlman]),
(birthdate:TEXT, Examples: [1963-05-04, 1975-03-30, 1969-12-04]),
(birth_name:TEXT, Examples: [Marc Edward Wilmore, Valentina Lantigua, Joseph Stewart Burns]),
(birth_place:TEXT, Examples: [USA, Brooklyn, Chicago]),
(birth_region:TEXT, Examples: [California, New York, Illinois]),
(birth_country:TEXT, Examples: [USA, Canada, Ireland]),
(height_meters:REAL, Examples: [1.85, 1.75, 2.03]),
(nickname:TEXT, Examples: [Jim, Doofus, Hoops])
]
# Table: Vote
[
(episode_id:TEXT, Examples: [S20-E1, S20-E10, S20-E11]),
(stars:INTEGER, Examples: [2, 3, 4]),
(votes:INTEGER, Examples: [16, 20, 36]),
(percent:REAL, Examples: [1.3, 1.7, 3.0])
]
# Table: Character_Award
[
(award_id:INTEGER, Examples: [325, 326, 327]),
(character:TEXT, Examples: [Homer Simpson, Moe Szyslak, Kent Brockman])
]
# Table: Episode
[
(episode_id:TEXT, Primary Key, Examples: [S20-E1, S20-E10, S20-E11]),
(season:INTEGER, Examples: [20]),
(episode:INTEGER, Examples: [1, 2, 3]),
(number_in_series:INTEGER, Examples: [421, 422, 423]),
(title:TEXT, Examples: [Sex, Pies and Idiot Scrapes]),
(summary:TEXT),
(air_date:TEXT, Examples: [2008-09-28, 2008-10-05, 2008-10-19]),
(episode_image:TEXT),
(rating:REAL, Examples: [7.2, 7.0, 7.1]),
(votes:INTEGER, Examples: [1192, 1055, 1015])
]
# Table: Keyword
[
(episode_id:TEXT, Primary Key, Examples: [S20-E1, S20-E10, S20-E11]),
(keyword:TEXT, Primary Key, Examples: [1930s to 2020s, erotic bakery, cake])
]
【Foreign keys】
Credit.episode_id=Episode.episode_id
Credit.person=Person.name
Award.person=Person.name
Award.episode_id=Episode.episode_id
Vote.episode_id=Episode.episode_id
Character_Award.award_id=Award.award_id
Keyword.episode_id=Episode.episode_id

    【Question】
    What are the keywords of the least popular episode? least popular episode refers to MIN(votes)

    【Evidence】
    least popular episode refers to MIN(votes)

    Please read and understand the database schema carefully, and generate an executable SQL based on the user's question and evidence. 

SQL: SELECT T2.keyword FROM Episode AS T1 INNER JOIN Keyword AS T2 ON T1.episode_id = T2.episode_id ORDER BY T1.votes LIMIT 1;