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: which video games was supported by prototype? 
Knowledge Triplets: Prototype, cvg.computer_videogame.gameplay_modes, Single-player video game
Horror, cvg.cvg_genre.games, Prototype
Prototype, cvg.computer_videogame.game_series, Prototype 2
Action role-playing game, cvg.cvg_genre.games, Prototype
Activision, cvg.cvg_publisher.games_published, Prototype
Prototype, cvg.game_series.games_in_series, Prototype
Prototype, cvg.computer_videogame.cvg_genre, Horror
Prototype 2, cvg.computer_videogame.release_date, 2012-04-24
Single-player video game, cvg.gameplay_mode.games_with_this_mode, Prototype
Prototype, cvg.video_game_soundtrack.video_game, Prototype
Prototype, cvg.game_version.game, Prototype
Prototype, cvg.computer_videogame.cvg_genre, Action-adventure game
Sandbox, cvg.cvg_genre.games, Prototype
Prototype 2, base.wikipedia_infobox.video_game.platforms, PlayStation 4
m.0v6w1xv, dataworld.gardening_hint.last_referenced_by, Prototype
Prototype, cvg.computer_videogame.developer, Radical Entertainment
Prototype, base.wikipedia_infobox.video_game.platforms, PlayStation 4
Prototype 2, cvg.computer_videogame.publisher, Activision
Single-player video game, cvg.gameplay_mode.games_with_this_mode, Prototype 2
Radical Entertainment, cvg.cvg_developer.games_developed, Prototype 2
Prototype, cvg.computer_videogame.publisher, Sierra Entertainment
Prototype 2, cvg.computer_videogame.gameplay_modes, Single-player video game
Prototype, user.avh.default_domain.ellerdale_topic.ellerdale_id, 0080-000f
Prototype 2, base.wikipedia_infobox.video_game.platforms, Microsoft Windows
Prototype, cvg.game_series.games_in_series, Prototype 2
Prototype, base.wikipedia_infobox.video_game.platforms, Microsoft Windows
Prototype, base.wikipedia_infobox.video_game.platforms, Xbox One
Action game, cvg.cvg_genre.games, Prototype
Prototype 2, cvg.computer_videogame.developer, Radical Entertainment
Prototype, imdb.topic.title_id, tt1233574
Action-adventure game, cvg.cvg_genre.games, Prototype
Science Fiction, cvg.cvg_genre.games, Prototype
Sierra Entertainment, cvg.cvg_publisher.games_published, Prototype
Prototype, cvg.computer_videogame.cvg_genre, Science Fiction
Prototype 2, base.wikipedia_infobox.video_game.platforms, Xbox One
Prototype, cvg.computer_videogame.publisher, Activision
Prototype, cvg.computer_videogame.cvg_genre, Sandbox
Prototype, cvg.computer_videogame.release_date, 2009-06-09
Prototype, cvg.computer_videogame.versions, Prototype
Prototype, base.wikipedia_infobox.video_game.platforms, PlayStation 3
Activision Blizzard, cvg.cvg_publisher.games_published, Prototype
Activision, cvg.cvg_publisher.games_published, Prototype 2
Prototype, cvg.computer_videogame.game_series, Prototype
Prototype, cvg.computer_videogame.soundtracks, Prototype
Prototype 2, base.wikipedia_infobox.video_game.platforms, PlayStation 3
Prototype, cvg.computer_videogame.publisher, Activision Blizzard
Prototype 2, base.wikipedia_infobox.video_game.developer, Radical Entertainment
Prototype, cvg.computer_videogame.cvg_genre, Action role-playing game
Prototype, base.wikipedia_infobox.video_game.developer, Radical Entertainment
Prototype, base.wikipedia_infobox.video_game.platforms, Xbox 360
Prototype, cvg.computer_videogame.cvg_genre, Action game
Radical Entertainment, cvg.cvg_developer.games_developed, Prototype
Prototype 2, base.wikipedia_infobox.video_game.platforms, Xbox 360
Prototype 2, cvg.computer_videogame.game_series, Prototype

Answer: Prototype
Prototype 2