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: the japanese submarine i-29 was built by which ship builder? 
Knowledge Triplets: Japanese submarine I-29, user.patrick.default_domain.warship_v1_1.crew, m.02kkddq
Type B1 submarine, user.patrick.default_domain.submarine_class.test_depth_m, 100.0
g.1215jd70, boats.ship.ship_class, Type B1 submarine
m.0r7tbcx, dataworld.gardening_hint.last_referenced_by, Japanese submarine I-29
Japanese submarine I-21, boats.ship.ship_class, Type B1 submarine
Type B1 submarine, boats.ship_class.ships_in_class, g.1218fgpc
Type B1 submarine, user.patrick.default_domain.submarine_class.submarine_type_ex_diesel_electric, Diesel-electric transmission
Type B1 submarine, boats.ship_class.ships_in_class, Japanese submarine I-30
g.122hp85c, boats.ship.ship_class, Type B1 submarine
m.019h, type.permission.controls, m.0r7tbcx
Japanese submarine I-29, boats.ship.ship_builder, Yokosuka Naval Yard
Type B1 submarine, boats.ship_class.ships_in_class, g.120j3l2h
Type B1 submarine, boats.ship_class.ships_in_class, Japanese submarine I-34
Japanese submarine I-15, boats.ship.ship_class, Type B1 submarine
Type B1 submarine, boats.ship_class.ships_in_class, Japanese submarine I-29
Type B1 submarine, boats.ship_class.displacement_tons, 2584.0
Type B1 submarine, boats.ship_class.armament, m.02kkcqs
Type B1 submarine, user.patrick.default_domain.submarine_class.displacement_submerged_tons, 3654.0
Japanese submarine I-29, boats.ship.draught, 5.12
Type B1 submarine, boats.ship_class.ships_in_class, Japanese submarine I-21
Japanese submarine I-29, boats.ship.ship_class, Type B1 submarine
Type B1 submarine, boats.ship_class.ships_in_class, g.1211qb1m
Type B1 submarine, boats.ship_class.ships_in_class, g.121pk2kz
Japanese submarine I-29, boats.ship.keel_laid, 1940-09-29
Japanese submarine I-29, boats.ship.length_overall, 108.5
Type B1 submarine, boats.ship_class.ships_in_class, Japanese submarine I-25
Type B1 submarine, boats.ship_class.max_speed_knots, 23.5
Type B1 submarine, boats.ship_class.ships_in_class, g.122hp85c
Type B1 submarine, user.patrick.default_domain.submarine_class.max_speed_submerged_km_h, 8.0
g.1218fgpc, boats.ship.ship_class, Type B1 submarine
Japanese submarine I-30, boats.ship.ship_class, Type B1 submarine
Japanese submarine I-29, boats.ship_builder.ships_built, Yokosuka Naval Yard
Yokosuka Naval Yard, boats.ship_builder.ships_built, Japanese submarine I-29
Type B1 submarine, boats.ship_class.ships_in_class, Japanese submarine I-19
g.1211qb1m, boats.ship.ship_class, Type B1 submarine
g.120j3l2h, boats.ship.ship_class, Type B1 submarine
Japanese submarine I-34, boats.ship.ship_class, Type B1 submarine
Type B1 submarine, boats.ship_class.armament, m.02kkcr1
Japanese submarine I-26, boats.ship.ship_class, Type B1 submarine
m.02kkddq, user.patrick.default_domain.warship_crew_tenure.ship, Japanese submarine I-29
Japanese submarine I-19, boats.ship.ship_class, Type B1 submarine
g.121pk2kz, boats.ship.ship_class, Type B1 submarine
m.02kkddq, user.patrick.default_domain.warship_crew_tenure.from, 1942-02-27
m.0r7tbcx, type.object.permission, m.019h
Type B1 submarine, boats.ship_class.ships_in_class, Japanese submarine I-26
m.0rjw7wy, dataworld.gardening_hint.last_referenced_by, Type B1 submarine
Type B1 submarine, boats.ship_class.ships_in_class, g.1215jd70
Type B1 submarine, boats.ship_class.ships_in_class, g.120rs0cj
Japanese submarine I-29, user.patrick.default_domain.warship_v1_1.commissioned, 1942-02-27
m.0tt8w2s, dataworld.gardening_hint.last_referenced_by, m.0r7tbcx
g.120rs0cj, boats.ship.ship_class, Type B1 submarine
m.02kkddq, user.patrick.default_domain.warship_crew_tenure.person, Izu Juichi
Japanese submarine I-25, boats.ship.ship_class, Type B1 submarine
Type B1 submarine, boats.ship_class.ships_in_class, Japanese submarine I-15
Izu Juichi, military.military_person.served_aboard, m.02kkddq
m.02kkddq, user.patrick.default_domain.warship_crew_tenure.role_co_xo, Commanding officer
Type B1 submarine, base.schemastaging.context_name.pronunciation, m.01315_5l

Answer: Yokosuka Naval Yard