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 home of President Barack Obama is the place that selected Vincent C. Gray to hold public office? 
Knowledge Triplets: Vincent C. Gray, people.person.spouse_s, m.0101mvbs
Barack Obama, broadcast.producer.location, Washington, D.C.
Vincent C. Gray, people.person.children, Jonice Gray Tucker
Barack Obama Extends Historical Legacy \"Astride the Promise of Change\", book.written_work.subjects, Presidency of Barack Obama
m.010p3jbd, government.government_position_held.appointed_by, Barack Obama
m.010hc1p6, government.government_position_held.appointed_by, Barack Obama
Barack Obama, government.political_appointer.appointees, m.0jb8k42
Barack Obama, government.politician.government_positions_held, m.04s_2dh
Official portrait of Barack Obama, common.image.size, m.059x9bc
m.0wzl8x_, government.government_position_held.appointed_by, Barack Obama
Barack Obama, government.political_appointer.appointees, m.05g5040
Family of Barack Obama, common.topic.webpage, m.0b48wwv
Barack Obama 2009 presidential inauguration, base.culturalevent.event.entity_involved, Joe Biden
Barack Obama, Sr., people.person.sibling_s, m.0k6m6kc
Barack Obama, Sr., people.person.children, David Ndesandjo
Barack Obama, people.person.spouse_s, m.02nqglv
Vincent Carlos Gray, freebase.valuenotation.has_value, Place of birth
Barack Obama, base.popstra.celebrity.supporter, m.063wq51
Barack Obama, government.political_appointer.appointees, m.05bj120
m.0jb8k42, government.government_position_held.appointed_by, Barack Obama
Vincent C. Gray, people.person.place_of_birth, Washington, D.C.
Barack Obama, Sr., people.person.spouse_s, m.0j4l4yg
Barack Obama, people.person.education, m.0nbyj44
Mayor of the District of Columbia, common.topic.image, Vincent C. Gray, Mayor of DC, January 2, 2011
m.0v4q6n5, government.government_position_held.appointed_by, Barack Obama
Vincent C. Gray, people.person.nationality, United States of America
Inside the Obama White House, common.topic.notable_types, Award-Winning Work
Jonice Gray Tucker, people.person.parents, Vincent C. Gray
Barack Obama, base.popstra.celebrity.friendship, m.063wnr6
m.05f_33k, government.government_position_held.appointed_by, Barack Obama
Barack Obama, government.political_appointer.appointees, m.0527js1
Barack Obama in comics, fictional_universe.fictional_character.place_of_birth, Honolulu
Barack Obama, government.political_appointer.appointees, m.09rg1bz
Family of Barack Obama, people.family.members, Barack Obama
Barack Obama Senate Portrait, common.image.size, m.02b54jd
m.0znj0g4, government.government_position_held.appointed_by, Barack Obama
Barack Obama, Sr., people.person.children, George Obama
Bo, base.presidentialpets.white_house_pet.member_of, Family of Barack Obama
m.0w25ghz, government.government_position_held.appointed_by, Barack Obama
m.05gmrjl, people.place_lived.person, Barack Obama
Barack Obama, base.popstra.celebrity.religion, m.063wq5t
Official portrait of Barack Obama, common.image.appears_in_topic_gallery, Maine Democratic caucuses, 2008
Barack Obama, people.person.employment_history, m.02nqgq1
Barack Obama, government.political_appointer.appointees, m.0wkxqyy
Barack Obama, Sr., people.person.nationality, Kenya
m.052m8b1, government.government_position_held.appointed_by, Barack Obama
Family of Barack Obama, common.topic.article, m.06_wyyv
Vincent C. Gray, common.topic.notable_types, Politician
m.09rg1bz, government.government_position_held.appointed_by, Barack Obama
m.05bj130, government.government_position_held.appointed_by, Barack Obama
m.09w3qtm, government.government_position_held.appointed_by, Barack Obama
Barack Obama 2009 presidential inauguration, base.culturalevent.event.entity_involved, John Roberts
m.0k1bj5t, government.government_position_held.office_holder, Vincent C. Gray
Barack Obama, government.political_appointer.appointees, m.0k06hnf
Barack Obama, Sr., people.person.education, m.04hg7hb
Barack Obama, people.person.education, m.02nqgp6
Barack Obama, base.firsts.first.achievements, m.04wrwjv
m.05gwyg2, government.government_position_held.appointed_by, Barack Obama
m.05bh__x, government.government_position_held.appointed_by, Barack Obama
Barack Obama, government.political_appointer.appointees, m.0nd7wz9
Vincent C. Gray, common.topic.notable_for, g.12571zvj7
m.0jtqj5c, government.government_position_held.appointed_by, Vincent C. Gray
Barack Obama, government.political_appointer.appointees, m.0w25ghz
A Moment in History: The Inauguration of Barack Obama, film.film.country, United States of America
m.010g2w70, government.government_position_held.appointed_by, Barack Obama
Barack Obama, government.political_appointer.appointees, m.010qp4_t
m.0bvbn3r, government.government_position_held.appointed_by, Barack Obama
Barack Obama, government.political_appointer.appointees, m.0r5y214
m.04s_x47, people.place_lived.person, Barack Obama
m.05bh_ms, government.government_position_held.appointed_by, Barack Obama
Barack Obama, base.popstra.celebrity.friendship, m.065pnsk
Barack Obama 2009 presidential inauguration, common.topic.image, US President Barack Obama taking his Oath of Office - 2009Jan20
Barack Obama, people.person.ethnicity, Irish American
m.04_5kfv, government.government_position_held.appointed_by, Barack Obama
m.05snpqk, base.famouspets.pet_ownership.owner, Barack Obama
Barack Obama presidential primary campaign, 2008, common.topic.image, Flickr Obama Springfield 01
Barack Obama, Sr., people.person.profession, Politician
Barack Obama, government.political_appointer.appointees, m.0118nrhq
m.0b497ny, common.webpage.topic, Family of Barack Obama
Family of Barack Obama, common.topic.webpage, m.0b497ny
U.S. Senator Barack Obama Podcast, broadcast.content.location, Washington, D.C.
Barack Obama Academy, location.location.geolocation, m.012270h6
Barack Obama, government.political_appointer.appointees, m.052lwd3
Barack Obama, common.topic.image, Official portrait of Barack Obama
m.05nd5t7, government.government_position_held.appointed_by, Barack Obama
m.05bp1tv, government.government_position_held.appointed_by, Barack Obama
Barack Obama, government.political_appointer.appointees, m.0zrhnnr
Barack Obama, government.political_appointer.appointees, m.05bhs1w
Barack Obama, base.popstra.organization.supporter, m.0645nnh
Barack Obama, people.person.education, m.02nqgpk
Barack Obama, common.topic.notable_for, g.1258j10lr
m.09vkg_2, government.government_position_held.appointed_by, Barack Obama
Barack Obama, people.person.quotations, Just give it a try
Barack Obama, government.political_appointer.appointees, m.05bp2yr
Barack Obama, Sr., people.person.education, m.04hg7h5
m.0zrhnnr, government.government_position_held.appointed_by, Barack Obama
Vincent C. Gray, freebase.valuenotation.has_value, Parents
Barack Obama, government.political_appointer.appointees, m.0q4mpmt
Barack Obama, people.person.sibling_s, m.0n4sql0
Barack Obama, government.political_appointer.appointees, m.0q4lvc7
Barack Obama, people.person.sibling_s, m.0n4sqkk
m.0jtlxf_, government.government_position_held.appointed_by, Barack Obama
Barack Obama, people.person.education, m.02nqgmw
Brad Pfaff, common.topic.image, Official portrait of Barack Obama
Vincent C. Gray, common.topic.image, Vincent C. Gray, Mayor of DC, January 2, 2011
Family of Barack Obama, common.topic.notable_for, g.12575gdnp
Official portrait of Barack Obama, common.image.appears_in_topic_gallery, 2008 Iowa Democratic caucuses
m.05bj04r, government.government_position_held.appointed_by, Barack Obama
Barack Obama, people.person.education, m.0nbyhy_
Official portrait of Barack Obama, common.image.appears_in_topic_gallery, Barack Obama assassination plot in Tennessee
Vincent C. Gray, Mayor of DC, January 2, 2011, common.image.appears_in_topic_gallery, Mayor of the District of Columbia
m.0w8v5d0, government.government_position_held.appointed_by, Barack Obama
Barack Obama, government.political_appointer.appointees, m.0w8v5d0
Barack Obama, government.political_appointer.appointees, m.0tlzpxk
Barack Obama, government.political_appointer.appointees, m.07nt04k
Barack Obama, government.political_appointer.appointees, m.064d51m
Vincent C. Gray, Mayor of DC, January 2, 2011, common.image.size, m.03sdy2c
m.0j34rt6, government.government_position_held.appointed_by, Barack Obama
Barack Obama, government.politician.party, m.03gjhww
Barack Obama, base.popstra.celebrity.wears, m.063wpzw
m.0j35vth, government.government_position_held.appointed_by, Barack Obama
Barack Obama 2009 presidential inauguration, base.inaugurations.inauguration.president, Barack Obama
m.0118nrhq, government.government_position_held.appointed_by, Barack Obama
Barack Obama, government.political_appointer.appointees, m.05lmlyn
Barack Obama, Sr., people.person.sibling_s, m.0wzjdyf
Official portrait of Barack Obama, common.image.appears_in_topic_gallery, United States presidential election in South Carolina, 2008
m.052lwd3, government.government_position_held.appointed_by, Barack Obama
Barack Obama, Sr., people.person.place_of_birth, Nyang'oma Kogelo
Barack Obama, government.political_appointer.appointees, m.05g438r
Barack Obama, government.political_appointer.appointees, m.0v4q6n5
Barack Obama, government.political_appointer.appointees, m.0q4ng3y
m.0k9_4xg, government.government_position_held.appointed_by, Barack Obama
Barack Obama, government.political_appointer.appointees, m.0j34rt6
m.05g438r, government.government_position_held.appointed_by, Barack Obama
Barack Obama, people.person.parents, Barack Obama, Sr.
m.05ctx2h, government.government_position_held.appointed_by, Barack Obama
m.010qyt8y, government.government_position_held.appointed_by, Barack Obama
Yes We Can: A Biography of President Barack Obama, common.topic.notable_for, g.125brs5d9
Barack Obama 2009 presidential inauguration, base.schemastaging.context_name.pronunciation, m.01315gcz
m.09knk78, government.government_position_held.appointed_by, Barack Obama
Barack Obama, people.person.profession, Lawyer
Barack Obama, people.person.profession, Politician
m.05g2cp1, government.government_position_held.appointed_by, Barack Obama
m.05bh_kg, government.government_position_held.appointed_by, Barack Obama
m.05g5040, government.government_position_held.appointed_by, Barack Obama
m.0q4lvc7, government.government_position_held.appointed_by, Barack Obama
Barack Obama, government.political_appointer.appointees, m.0k9_6d4
Barack Obama, freebase.valuenotation.is_reviewed, Place of birth
Malia Ann Obama, people.person.place_of_birth, Chicago
m.0r60ybv, government.government_position_held.appointed_by, Barack Obama
Barack Obama, people.person.education, m.012l94sv
Barack Obama, government.political_appointer.appointees, m.0jtmkth
m.05lmlyn, government.government_position_held.appointed_by, Barack Obama
m.03xdtyk, people.place_lived.person, Barack Obama
Barack Obama, people.person.nationality, United States of America
m.03h96h6, government.government_position_held.office_holder, Barack Obama
Michelle Obama, people.person.place_of_birth, Chicago
Barack Obama, broadcast.producer.location, Washington, D.C.
m.07nt04k, government.government_position_held.appointed_by, Barack Obama
Vincent C. Gray, people.person.gender, Male
m.0b48wwv, common.webpage.topic, Family of Barack Obama
Barack Obama, government.political_appointer.appointees, m.05ctx2h
m.0wzl8h_, government.government_position_held.appointed_by, Barack Obama
Barack Obama, people.person.places_lived, m.04s_x47
m.0jtmkth, government.government_position_held.appointed_by, Barack Obama
m.03xdty5, people.place_lived.person, Barack Obama
Barack Obama, base.popstra.organization.supporter, m.064shtq
Barack Obama, government.political_appointer.appointees, m.010g2w70
Barack Obama, government.political_appointer.appointees, m.05nd5t7
Barack Obama, base.popstra.celebrity.friendship, m.065pk99
Barack Obama 2009 presidential inauguration, time.event.locations, United States Capitol
m.010g2xdb, government.government_position_held.appointed_by, Barack Obama
Vincent C. Gray, people.person.education, m.0n1nccv
Barack Obama, people.person.education, m.012m9zwm
m.0ccfkl4, people.place_lived.person, Barack Obama
m.010g2c43, government.government_position_held.appointed_by, Barack Obama
m.05bhv8k, government.government_position_held.appointed_by, Barack Obama
Vincent C. Gray, people.person.education, m.08crvjy
Barack Obama, government.political_appointer.appointees, m.05ftbw9
Barack Obama, people.person.education, m.012m4x3m
Family of Barack Obama, people.family.members, Michelle Obama
Barack Obama, people.person.places_lived, m.03xdty5
Barack Obama, book.book_subject.works, A Writer's Journey to Selma, Alabama
Barack Obama, government.us_president.vice_president, Joe Biden
Barack Obama, government.political_appointer.appointees, m.0115sj6s
Barack Obama, government.political_appointer.appointees, m.010g2xdb
Vincent C. Gray, government.political_appointer.appointees, m.0jtqj5c
Barack Obama: People's President, film.film.country, United States of America
m.03xdtyc, people.place_lived.person, Barack Obama
Barack Obama, people.person.sibling_s, m.0kv53fr
Barack Obama, people.person.employment_history, m.02nqgy7
Barack Obama, Sr., people.person.parents, Habiba Akumu Obama
Barack Obama, people.person.places_lived, m.0ccfkl4
Barack Obama, base.famouspets.pet_owner.pets_owned, m.05snpqk
Yes We Can: A Biography of President Barack Obama, book.written_work.subjects, United States of America
Barack Obama, government.political_appointer.appointees, m.05bj130
m.0glx1wx, government.government_position_held.appointed_by, Barack Obama
Barack Obama 2009 presidential inauguration, base.culturalevent.event.entity_involved, Barack Obama
Barack Obama, Sr., people.person.children, Bernard Obama
Barack Obama, government.political_appointer.appointees, m.05gwyg2
Barack Obama, people.person.ethnicity, Multiracial American
Inside the Obama White House, film.film.personal_appearances, m.0ncztwv
Family of Barack Obama, common.topic.image, Family of Barack Obama
Vincent C. Gray, people.person.profession, Politician
Barack Obama 2009 presidential inauguration, base.inaugurations.inauguration.inaugural_address, Inaugural Address of Barack Obama
Barack Obama, people.person.sibling_s, m.0n4sqkd
Barack Obama, base.popstra.celebrity.friendship, m.063wnrl
Barack Obama, Sr., people.person.children, Abo Obama
Barack Obama, people.person.education, m.012m11bj
Barack Obama: People's President, film.film.country, South Africa
m.0dfzl4x, architecture.occupancy.occupant, Barack Obama
Vincent Carlos Gray, people.person.nationality, United States of America
Barack Obama, government.political_appointer.appointees, m.052m8b1
m.05bht4v, government.government_position_held.appointed_by, Barack Obama
Barack Obama, base.popstra.organization.supporter, m.064fnt0
Official portrait of Barack Obama, common.image.appears_in_topic_gallery, Maryland Democratic primary, 2008
Barack Obama 2009 presidential inauguration, common.topic.webpage, m.0b6rs3n
m.0q4ng3y, government.government_position_held.appointed_by, Barack Obama
m.0gw2w11, government.political_party_tenure.politician, Vincent C. Gray
Barack Obama, government.political_appointer.appointees, m.09knk78
Barack Obama, base.popstra.celebrity.friendship, m.065pj13
m.05bh_20, government.government_position_held.appointed_by, Barack Obama
m.0101mvbs, people.marriage.spouse, Vincent C. Gray
m.05v3kv0, government.government_position_held.appointed_by, Barack Obama
Barack Obama, base.litcentral.named_person.individual_names, m.07qvn18
Vincent C. Gray, government.politician.party, m.0gw2w11
Barack Obama, Sr., people.person.children, Mark Okoth Obama Ndesandjo
Barack Obama, government.political_appointer.appointees, m.010p3jbd
Barack Obama, government.politician.election_campaigns, Barack Obama 1996 Illinois Senate Campaign
m.0tm2t1f, government.government_position_held.appointed_by, Barack Obama
m.0jtl_wm, government.government_position_held.appointed_by, Barack Obama
Barack Obama, government.political_appointer.appointees, m.0r60ybv
Barack Obama, Sr., people.deceased_person.place_of_death, Nairobi
m.05bhs1w, government.government_position_held.appointed_by, Barack Obama
Barack Obama, government.politician.government_positions_held, m.03h9hn4
m.05bj0_8, government.government_position_held.appointed_by, Barack Obama
m.05pv1bq, government.government_position_held.appointed_by, Barack Obama
Family of Barack Obama, people.family.members, Malia Ann Obama
Vincent Carlos Gray, freebase.valuenotation.has_value, Date of birth
Barack Obama, government.political_appointer.appointees, m.010qyt8y
m.05bh_5w, government.government_position_held.appointed_by, Barack Obama
United States Capitol, location.location.events, Barack Obama 2009 presidential inauguration
Barack Obama, people.person.profession, Writer
Barack Obama 2009 presidential inauguration, common.topic.notable_for, g.1259p3566
m.0jb89c0, government.government_position_held.appointed_by, Barack Obama
Barack Obama, base.popstra.celebrity.friendship, m.063qv6w
Barack Obama, government.political_appointer.appointees, m.010g2x8g
By the People: The Election of Barack Obama, film.film.country, United States of America
m.0k9_61x, government.government_position_held.appointed_by, Barack Obama
m.0n1nccv, education.education.student, Vincent C. Gray
Vincent C. Gray, people.person.place_of_birth, Washington, D.C.
Barack Obama, architecture.building_occupant.buildings_occupied, m.0dfzl4x
m.0527js1, government.government_position_held.appointed_by, Barack Obama
Barack Obama, base.popstra.celebrity.friendship, m.065pnvm
m.0wkxqyy, government.government_position_held.appointed_by, Barack Obama
United States presidential election, 2008, base.culturalevent.event.entity_involved, Barack Obama
President Barack Obama: The Man and His Journey, film.film.country, United States of America
Barack Obama, people.person.places_lived, m.03xdtyk
Barack Obama, people.person.ethnicity, English American
m.05bp2yr, government.government_position_held.appointed_by, Barack Obama
Barack Obama, base.popstra.organization.supporter, m.0652fz5
Barack Obama, common.topic.article, m.09s453y
President of the United States, common.topic.image, Official portrait of Barack Obama
Family of Barack Obama, common.topic.notable_types, Family
Barack Obama, people.person.children, Natasha Obama
m.010qp4_t, government.government_position_held.appointed_by, Barack Obama
Family of Barack Obama, common.topic.image, Obamas at White House Easter Egg Roll 4-13-09 2
Barack Obama, Sr., people.person.profession, Economist
m.05gh7qx, government.government_position_held.appointed_by, Barack Obama
Yes We Can: A Biography of President Barack Obama, common.topic.notable_types, Book
Barack Obama, base.popstra.celebrity.supporter, m.063wq59
Vincent Carlos Gray, common.topic.notable_types, Person
Barack Obama, government.political_appointer.appointees, m.04_5lb8
Barack Obama, base.politicalconventions.presidential_nominee.nominated_at, 2008 Democratic National Convention
m.05bh_yd, government.government_position_held.appointed_by, Barack Obama
Barack Obama, base.popstra.organization.supporter, m.06505l2
Barack Obama, Sr., people.person.parents, Hussein Onyango Obama
Barack Obama, base.popstra.celebrity.friendship, m.065pfvf
Barack Obama, people.person.places_lived, m.03xdtyc
Official portrait of Barack Obama, common.image.appears_in_topic_gallery, Multiracial American
Barack Obama, government.political_appointer.appointees, m.0glx1wx
m.052mbx6, government.government_position_held.appointed_by, Barack Obama
m.05ftbw9, government.government_position_held.appointed_by, Barack Obama
Barack Obama, Sr., people.person.spouse_s, m.0j4l4y8
Family of Barack Obama, base.presidentialpets.first_family.pets, Bo
m.0b49520, common.webpage.topic, Family of Barack Obama
Barack Obama, people.family_member.family, Family of Barack Obama
Barack Obama, people.person.employment_history, m.02nqgqh
Barack Obama, government.political_appointer.appointees, m.010g2c43
Vincent C. Gray, common.topic.article, m.07t0zb
Vincent C. Gray, Mayor of DC, January 2, 2011, common.image.appears_in_topic_gallery, Vincent C. Gray
Barack Obama: People's President, film.film.personal_appearances, m.0gyyxd1
Barack Obama, base.popstra.celebrity.vacations_in, m.063wq3l
m.010g2x8g, government.government_position_held.appointed_by, Barack Obama
Barack Obama, people.person.ethnicity, Kenyan American
Yes We Can: A Biography of President Barack Obama, common.topic.image, barack.jpg
Official portrait of Barack Obama, common.image.appears_in_topic_gallery, President of the United States
Barack Obama, people.person.sibling_s, m.0n4sqh8
Barack Obama, Sr., people.person.children, Auma Obama
m.0tlzpxk, government.government_position_held.appointed_by, Barack Obama
Barack Obama 2009 presidential inauguration, base.newsevents.news_reported_event.news_report_s, m.07wx5qs
m.0nd7wz9, government.government_position_held.appointed_by, Barack Obama
Barack Obama, people.person.sibling_s, m.0n4sqk2
m.08crvjy, education.education.student, Vincent C. Gray
Malik Abongo Obama, people.person.place_of_birth, Nairobi
Barack Obama, people.person.education, m.02nqgn2
Barack Obama, Sr., people.person.spouse_s, m.040fvqp
Vincent C. Gray, government.politician.government_positions_held, m.0k1bj5t
Barack Obama, people.person.places_lived, m.05gmrjl
Barack Obama, Sr., common.topic.article, m.03qccxn
m.0q4mpmt, government.government_position_held.appointed_by, Barack Obama
Vincent C. Gray, people.person.religion, Catholicism
Official portrait of Barack Obama, common.image.appears_in_topic_gallery, Louisiana Democratic primary, 2008
Barack Obama, government.political_appointer.appointees, m.0jb89c0
Barack Obama, base.popstra.celebrity.supporter, m.063wq4q
Barack Obama, government.political_appointer.appointees, m.052mbx6
Family of Barack Obama, common.topic.webpage, m.0b49520
Official portrait of Barack Obama, common.image.appears_in_topic_gallery, Presidency of Barack Obama
m.0r5y214, government.government_position_held.appointed_by, Barack Obama
Barack Obama, base.popstra.celebrity.friendship, m.063s48m
Barack Obama, base.inaugurations.inauguration_speaker.inauguration, Barack Obama 2009 presidential inauguration
Barack Obama, people.person.place_of_birth, Honolulu
Barack Obama in His Own Words, book.book_edition.place_of_publication, New York City
Official portrait of Barack Obama, common.image.appears_in_topic_gallery, Brad Pfaff
m.04s_2dh, government.government_position_held.office_holder, Barack Obama
Natasha Obama, people.person.place_of_birth, Chicago
m.03h9hn4, government.government_position_held.office_holder, Barack Obama
Barack Obama, government.political_appointer.appointees, m.010hc1p6
m.0k06hnf, government.government_position_held.appointed_by, Barack Obama
m.0115sj6s, government.government_position_held.appointed_by, Barack Obama
m.0k9_6d4, government.government_position_held.appointed_by, Barack Obama
m.04_5lb8, government.government_position_held.appointed_by, Barack Obama
Vincent C. Gray, people.person.children, Vincent Carlos Gray
Barack Obama 2009 presidential inauguration, base.culturalevent.event.entity_involved, John Paul Stevens
m.064d51m, government.government_position_held.appointed_by, Barack Obama
Barack Obama, government.political_appointer.appointees, m.0bvbn3r
Vincent Carlos Gray, people.person.parents, Vincent C. Gray
Barack Obama, people.person.education, m.012m6w18
Multiracial American, common.topic.image, Official portrait of Barack Obama
Barack Obama, people.person.employment_history, m.02nqgsc
Yes We Can: A Biography of President Barack Obama, book.book.genre, Biography
Official portrait of Barack Obama, common.image.appears_in_topic_gallery, Barack Obama
Family of Barack Obama, common.topic.image, Obama family portrait in the Green Room
Barack Obama, government.political_appointer.appointees, m.05g2cp1
Barack Obama, people.person.parents, Ann Dunham
m.0w2cph_, government.government_position_held.appointed_by, Barack Obama
Barack Obama, government.political_appointer.appointees, m.0znj0g4
Barack Obama, people.person.profession, Author
Family of Barack Obama, people.family.members, Natasha Obama
Barack Obama Senate Portrait, common.image.appears_in_topic_gallery, Current heads of state
Barack Obama, government.political_appointer.appointees, m.05gh7qx
Barack Obama, people.person.education, m.0nbyhqc
m.04_2vlm, government.government_position_held.appointed_by, Barack Obama
Barack Obama, people.person.sibling_s, m.0kv53ff
Barack Obama, base.firsts.first.achievements, m.05gmrc3
m.05kcjbj, government.government_position_held.appointed_by, Barack Obama
Yes We Can: A Biography of President Barack Obama, common.topic.article, m.064d40l
Barack Obama, government.politician.government_positions_held, m.03h96h6
Vincent Carlos Gray, common.topic.notable_for, g.1q3shksvl
Vincent Carlos Gray, people.person.gender, Male
m.05bj120, government.government_position_held.appointed_by, Barack Obama
Barack Obama, base.popstra.celebrity.vacations_in, m.063wq3b

Answer: Washington, D.C.