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: who was president in 1988 in the united states? 
Knowledge Triplets: President of the United States, common.topic.webpage, m.05ckhcc
m.09w6h41, common.webpage.topic, President of the United States
James A. Garfield, common.topic.notable_types, US President
Abraham Lincoln, people.person.nationality, United States of America
Millard Fillmore, government.us_vice_president.to_president, Zachary Taylor
President of the United States, fictional_universe.character_occupation.characters_with_this_occupation, Cast of Dasavathaaram
President of the United States, government.government_office_or_title.office_holders, m.03fx8c3
m.03fx817, government.government_position_held.office_position_or_title, President of the United States
Flag of the President of the United States, symbols.flag.used_by, m.0j9gyfv
m.02s9flj, government.government_position_held.office_position_or_title, President of the United States
President Pennybaker, book.written_work.subjects, President of the United States
President of the United States, government.government_office_or_title.office_holders, m.0446bdb
Lyndon B. Johnson, people.person.nationality, United States of America
m.04469xf, government.government_position_held.office_position_or_title, President of the United States
President number, rdf-schema#domain, US President
Vice President of the United States, common.topic.notable_types, Government Office or Title
William McKinley, people.person.nationality, United States of America
James Madison, common.topic.notable_types, US President
Harry S. Truman, common.topic.notable_types, US President
Richard Nixon, government.us_vice_president.to_president, Dwight D. Eisenhower
George Washington, first President of the United States, common.image.appears_in_topic_gallery, The Imperial Presidency
m.03fx8c3, government.government_position_held.office_position_or_title, President of the United States
President of the United States, award.award_presenting_organization.awards_presented, National Medal of Science
William McKinley, common.topic.notable_types, US President
Franklin Pierce, common.topic.notable_types, US President
Ronald Reagan, government.us_president.vice_president, George H. W. Bush
Matt Santos, fictional_universe.fictional_character.occupation, President of the United States
m.0663zsk, common.webpage.topic, President of the United States
Vice President of the United States, fictional_universe.character_occupation.characters_with_this_occupation, Jack Ryan
m.09xlnpm, common.webpage.resource, 'West Wing': The next Fake President of the United States is...
m.09ygxjq, common.webpage.topic, President of the United States
Richard Nixon, government.us_president.vice_president, Gerald Ford
President of the United States, book.book_subject.works, Burn Before Reading: Presidents, CIA Directors, and Secret Intelligence
President of the United States, common.topic.image, George Washington, first President of the United States
John Adams, government.us_president.vice_president, Thomas Jefferson
President of the United States, government.government_office_or_title.office_holders, m.03fx817
President of the United States, book.book_subject.works, President Pennybaker
Zachary Taylor, common.topic.notable_types, US President
m.09xlnpm, common.webpage.topic, President of the United States
Vice President of the United States, fictional_universe.character_occupation.characters_with_this_occupation, Lt. Cmdr. Robby Jackson
President of the United States, freebase.type_profile.equivalent_topic, US President
President of the United States, common.topic.webpage, m.09y9g34
President of the United States, common.topic.webpage, m.0hnjbwk
m.02kzpyv, government.government_position_held.office_holder, Ronald Reagan
President of the United States, freebase.equivalent_topic.equivalent_type, US President
Conrad Dalton, fictional_universe.fictional_character.occupation, President of the United States
'West Wing': The next Fake President of the United States is..., common.resource.annotations, m.09xlnpm
John F. Kennedy, government.us_president.vice_president, Lyndon B. Johnson
The Reader's Companion to the American Presidency, common.topic.notable_for, g.125bp0g1z
Barack Obama, common.topic.notable_types, US President
President of the United States, book.book_subject.works, The Sound of Leadership: Presidential Communication in the Modern Age
m.03fx7zy, government.government_position_held.office_position_or_title, President of the United States
US President, type.type.domain, Government
m.09y93hy, common.webpage.topic, President of the United States
Max for President, book.written_work.subjects, President of the United States
The Reader's Companion to the American Presidency, common.topic.notable_types, Book
President of the United States, government.government_office_or_title.office_holders, m.03fx7zy
Presidential Medal of Freedom, award.award.presented_by, President of the United States
Ulysses S. Grant, common.topic.notable_types, US President
President of the United States, government.government_office_or_title.office_holders, m.04s_2dh
The Reader's Companion to the American Presidency, book.written_work.editor, Alan Brinkley
m.04xdfjz, base.firsts.first_achievement.achievement, President of the United States
Millard Fillmore, common.topic.notable_types, US President
Herbert Hoover, common.topic.notable_types, US President
US President, freebase.type_profile.kind, Significant
Barack Obama, people.person.nationality, United States of America
m.0c1svhh, people.appointment.appointed_role, President of the United States
m.0b46f7h, common.webpage.topic, President of the United States
President of the United States, common.topic.notable_types, Government Office or Title
John Tyler, government.us_vice_president.to_president, William Henry Harrison
'West Wing': The next Fake President of the United States is..., common.resource.annotations, m.09xlnjq
Calvin Coolidge, common.topic.notable_types, US President
m.03fx838, government.government_position_held.office_position_or_title, President of the United States
President of the United States, award.award_presenting_organization.awards_presented, Presidential Medal of Freedom
President of the United States, government.government_office_or_title.office_holders, m.040b_7k
m.09ynr7x, common.webpage.topic, President of the United States
m.04469y1, government.government_position_held.office_position_or_title, President of the United States
Chester A. Arthur, government.us_vice_president.to_president, James A. Garfield
President of the United States, government.government_office_or_title.office_holders, m.02k6vpl
US President, freebase.type_hints.included_types, Topic
m.0446b8l, government.government_position_held.office_position_or_title, President of the United States
US President, common.topic.article, m.03yy9v6
m.03fx88b, government.government_position_held.office_position_or_title, President of the United States
m.03fx7j8, government.government_position_held.office_position_or_title, President of the United States
m.03fx8bt, government.government_position_held.office_position_or_title, President of the United States
President of the United States, base.firsts.achievement.firsts, m.08ntjg4
President of the United States, government.government_office_or_title.office_holders, m.04469y1
Madam President, book.written_work.subjects, President of the United States
President of the United States, fictional_universe.character_occupation.characters_with_this_occupation, President Thomas Westwood
m.04lsvx0, common.webpage.topic, President of the United States
m.09wvy_x, common.webpage.topic, President of the United States
Official portrait of Barack Obama, common.image.appears_in_topic_gallery, United States presidential election in South Carolina, 2008
President of the United States, fictional_universe.character_occupation.characters_with_this_occupation, Abraham Lincoln
President Thomas Westwood, fictional_universe.fictional_character.occupation, President of the United States
m.09xgz2n, common.webpage.topic, President of the United States
First Off the Tee: Presidential Hackers, Duffers, and Cheaters From Taft to Bush, book.written_work.subjects, President of the United States
Ulysses S. Grant, people.person.nationality, United States of America
Rutherford B. Hayes, common.topic.notable_types, US President
Chester A. Arthur, common.topic.notable_types, US President
George Washington, first President of the United States, common.image.appears_in_topic_gallery, George Washington
President of the United States, government.government_office_or_title.office_holders, m.03fx7j8
m.04466tx, government.government_position_held.office_position_or_title, President of the United States
President of the United States, government.government_office_or_title.office_holders, m.0446b8l
George W. Bush, people.person.nationality, United States of America
President of the United States, symbols.flag_referent.flag, m.0j9gyfv
US President, freebase.type_profile.equivalent_topic, President of the United States
What Do We Do Now?: A Workbook for the President-elect, book.written_work.subjects, President of the United States
The Moral Rhetoric of American Presidents, book.written_work.subjects, President of the United States
President of the United States, base.schemastaging.context_name.pronunciation, g.125_lw0zw
George Washington, government.us_president.vice_president, John Adams
Thomas Jefferson, government.us_vice_president.to_president, John Adams
Richard Nixon, common.topic.notable_types, US President
George W. Bush, common.topic.notable_types, US President
m.02h6phn, government.government_position_held.office_position_or_title, President of the United States
Martin Van Buren, common.topic.notable_types, US President
President of the United States, base.ontologies.ontology_instance.equivalent_instances, m.07nflbk
Lyndon B. Johnson, common.topic.notable_types, US President
Theodore Roosevelt, government.us_vice_president.to_president, William McKinley
Benjamin Harrison, common.topic.notable_types, US President
President of the United States, common.topic.webpage, m.09ygxjq
Ronald Reagan, people.person.nationality, United States of America
President of the United States, common.topic.article, m.060dd
Vice president, rdf-schema#domain, US President
President of the United States, government.government_office_or_title.office_holders, m.03fx85y
Lyndon B. Johnson, government.us_vice_president.to_president, John F. Kennedy
President of the United States, book.book_subject.works, Poem for a President: Midnight Flight of the Poetry Angels
President of the United States, government.government_office_or_title.office_holders, m.03fx82m
m.04469yh, government.government_position_held.office_position_or_title, President of the United States
Otto Runs for President, book.written_work.subjects, President of the United States
m.04wrx4g, base.firsts.first_achievement.achievement, President of the United States
President of the United States, common.topic.webpage, m.09ysj6g
President of the United States, fictional_universe.character_occupation.characters_with_this_occupation, Lt. Cmdr. Robby Jackson
President of the United States, business.employer.employees, m.0czp5hh
President of the United States, common.topic.webpage, m.0b464_j
Dwight D. Eisenhower, common.topic.notable_types, US President
m.09ysj6g, common.webpage.topic, President of the United States
m.07nflbk, base.ontologies.ontology_instance_mapping.freebase_topic, President of the United States
President of the United States, book.book_subject.works, What Do We Do Now?: A Workbook for the President-elect
m.0dj2gvv, base.ontologies.ontology_class_mapping.freebase_topic, President of the United States
Herbert Hoover, people.person.nationality, United States of America
President of the United States, government.government_office_or_title.office_holders, m.02s9flj
President of the United States, common.topic.webpage, m.09xm31x
Josiah Bartlet, fictional_universe.fictional_character.occupation, President of the United States
Abraham Lincoln, common.topic.notable_types, US President
William Howard Taft, common.topic.notable_types, US President
James K. Polk, common.topic.notable_types, US President
m.03fx7hy, government.government_position_held.office_position_or_title, President of the United States
President of the United States, fictional_universe.character_occupation.characters_with_this_occupation, Josiah Bartlet
President of the United States, base.firsts.achievement.firsts, m.04wrx4g
President of the United States, book.book_subject.works, Otto Runs for President
John Adams, government.us_vice_president.to_president, George Washington
Rutherford B. Hayes, people.person.nationality, United States of America
m.03q2h_9, government.government_position_held.office_position_or_title, President of the United States
President of the United States, book.book_subject.works, Presidential Command: Power, Leadership, and the Making of Foreign Policy from Richard Nixon to George W. Bush
The Reader's Companion to the American Presidency, book.written_work.subjects, President of the United States
President of the United States, government.government_office_or_title.office_holders, m.03fx83k
President of the United States, common.topic.webpage, m.09ynr7x
President of the United States, award.award_presenting_organization.award_categories_presented, National Medal of Technology and Innovation
William McKinley, government.us_president.vice_president, Theodore Roosevelt
The Reader's Companion to the American Presidency, book.written_work.editor, Davis Dyer
m.08ntjg4, base.firsts.first_achievement.achievement, President of the United States
Harry S. Truman, people.person.nationality, United States of America
US President, type.type.expected_by, US Presidents
President of the United States, book.book_subject.works, Presidential Leadership: Rating the Best and the Worst in the White House
m.03fx83k, government.government_position_held.office_position_or_title, President of the United States
President of the United States, book.book_subject.works, The Rhetorical Presidency
President of the United States, common.topic.webpage, m.0663zsk
President of the United States, common.topic.webpage, m.09xlnpm
m.0b464_j, common.webpage.topic, President of the United States
Warren G. Harding, government.us_president.vice_president, Calvin Coolidge
President of the United States, common.topic.webpage, m.09w6pyk
President of the United States, people.appointed_role.appointment, m.0c1svhh
President of the United States, government.government_office_or_title.office_holders, m.0446bcc
Abraham Lincoln, fictional_universe.fictional_character.occupation, President of the United States
William Henry Harrison, common.topic.notable_types, US President
m.0446bdb, government.government_position_held.office_position_or_title, President of the United States
President Thomas Westwood, common.topic.notable_for, g.1q5jd3v2c
President of the United States, common.topic.webpage, m.09y93hy
Grover Cleveland, people.person.nationality, United States of America
Jack Ryan, fictional_universe.fictional_character.occupation, President of the United States
President of the United States, government.government_position_held.office_position_or_title, m.02kzpyv
Ulysses S. Grant, fictional_universe.fictional_character.occupation, President of the United States
President of the United States, government.government_office_or_title.office_holders, m.02h6phn
President of the United States, government.government_office_or_title.jurisdiction, United States of America
United States of America, government.governmental_jurisdiction.government_positions, Vice President of the United States
White House Ghosts: Presidents and Their Speechwriters, book.written_work.subjects, President of the United States
m.040b_7k, government.government_position_held.office_position_or_title, President of the United States
Woodrow Wilson, people.person.nationality, United States of America
President of the United States, government.government_office_or_title.office_holders, m.04469y8
Theodore Roosevelt, common.topic.notable_types, US President
US President, freebase.type_hints.included_types, Person
Gerald Ford, common.topic.notable_types, US President
US President, freebase.type_profile.strict_included_types, Topic
George H. W. Bush, people.person.nationality, United States of America
President of the United States, fictional_universe.character_occupation.characters_with_this_occupation, Ulysses S. Grant
m.09xlnjq, common.webpage.resource, 'West Wing': The next Fake President of the United States is...
George Washington, common.topic.notable_types, US President
Dwight D. Eisenhower, government.us_president.vice_president, Richard Nixon
Zachary Taylor, government.us_president.vice_president, Millard Fillmore
m.05ckhcc, common.webpage.topic, President of the United States
George H. W. Bush, common.topic.notable_types, US President
Gerald Ford, people.person.nationality, United States of America
m.03fx7_v, government.government_position_held.office_position_or_title, President of the United States
President of the United States, common.topic.image, Official portrait of Barack Obama
President of the United States, government.government_office_or_title.office_holders, m.02hz5r6
Vice President of the United States, government.government_office_or_title.jurisdiction, United States of America
President of the United States, government.government_office_or_title.office_holders, m.03fx88m
President of the United States, government.government_office_or_title.office_holders, m.04466xm
The Reader's Companion to the American Presidency, book.book.genre, Non-fiction
President of the United States, government.government_office_or_title.office_holders, m.04466xz
President of the United States, government.government_office_or_title.office_holders, m.03fx8cf
Bill Clinton, common.topic.notable_types, US President
William Henry Harrison, government.us_president.vice_president, John Tyler
President of the United States, fictional_universe.character_occupation.characters_with_this_occupation, Matt Santos
George Washington, common.topic.image, George Washington, first President of the United States
Bill Clinton, people.person.nationality, United States of America
President of the United States, base.firsts.achievement.firsts, m.04wrwjv
m.03fx88m, government.government_position_held.office_position_or_title, President of the United States
m.04469y8, government.government_position_held.office_position_or_title, President of the United States
John Adams, common.topic.notable_types, US President
President of the United States, book.book_subject.works, Madam President
President of the United States, book.book_subject.works, The Reader's Companion to the American Presidency
US President, freebase.type_hints.included_types, Politician
President of the United States, government.government_office_or_title.jurisdiction, United States of America
James Buchanan, common.topic.notable_types, US President
Calvin Coolidge, government.us_vice_president.to_president, Warren G. Harding
m.09w6pyk, common.webpage.topic, President of the United States
President of the United States, government.government_office_or_title.office_holders, m.03fx7hy
President of the United States, government.government_office_or_title.office_holders, m.03fx899
m.04466xm, government.government_position_held.office_position_or_title, President of the United States
President of the United States, government.government_office_or_title.office_holders, m.0446b70
m.0446bcc, government.government_position_held.office_position_or_title, President of the United States
President of the United States, government.government_office_or_title.office_holders, m.03fx83v
Franklin D. Roosevelt, government.us_president.vice_president, Harry S. Truman
Gerald Ford, government.us_vice_president.to_president, Richard Nixon
m.03fx85y, government.government_position_held.office_position_or_title, President of the United States
President of the United States, government.government_office_or_title.office_holders, m.04469xf
President of the United States, government.government_office_or_title.office_holders, m.04466tx
The Rhetorical Presidency, book.written_work.subjects, President of the United States
m.04s_2dh, government.government_position_held.office_position_or_title, President of the United States
Presidential Command: Power, Leadership, and the Making of Foreign Policy from Richard Nixon to George W. Bush, common.topic.notable_for, g.125f9cm5z
President of the United States, common.topic.webpage, m.09wvy_x
Jimmy Carter, people.person.nationality, United States of America
Richard Nixon, people.person.nationality, United States of America
George Washington, first President of the United States, common.image.appears_in_topic_gallery, Town Destroyer
President of the United States, government.government_office_or_title.category, President
President of the United States, government.government_office_or_title.office_holders, m.03fx81_
Franklin D. Roosevelt, common.topic.notable_types, US President
President of the United States, government.government_office_or_title.office_holders, m.04469xv
Presidential Command: Power, Leadership, and the Making of Foreign Policy from Richard Nixon to George W. Bush, book.written_work.subjects, Politics of the United States
President of the United States, book.book_subject.works, White House Ghosts: Presidents and Their Speechwriters
Harry S. Truman, government.us_vice_president.to_president, Franklin D. Roosevelt
Lyndon B. Johnson, people.person.quotations, I'm the only president you've got.
Martin Van Buren, government.us_vice_president.to_president, Andrew Jackson
President of the United States, government.government_office_or_title.office_holders, m.03fx87q
President of the United States, government.government_office_or_title.office_holders, m.02kzpyv
m.03fx899, government.government_position_held.office_position_or_title, President of the United States
George Washington, first President of the United States, common.image.appears_in_topic_gallery, President of the United States
The Reader's Companion to the American Presidency, common.topic.article, m.0770wzg
m.04466xb, government.government_position_held.office_position_or_title, President of the United States
Lt. Cmdr. Robby Jackson, fictional_universe.fictional_character.occupation, Vice President of the United States
m.09xm31x, common.webpage.topic, President of the United States
George H. W. Bush, government.us_vice_president.to_president, Ronald Reagan
m.0446bdk, government.government_position_held.office_position_or_title, President of the United States
George Washington, first President of the United States, common.image.appears_in_topic_gallery, Charles Lee
President of the United States, government.government_office_or_title.office_holders, m.04466zr
Warren G. Harding, people.person.nationality, United States of America
President of the United States, government.government_office_or_title.office_holders, m.0446b9j
Woodrow Wilson, common.topic.notable_types, US President
James A. Garfield, government.us_president.vice_president, Chester A. Arthur
Jack Ryan, fictional_universe.fictional_character.occupation, Vice President of the United States
President of the United States, fictional_universe.character_occupation.characters_with_this_occupation, Conrad Dalton
Official portrait of Barack Obama, common.image.appears_in_topic_gallery, President of the United States
President of the United States, base.schemastaging.context_name.plural, m.0w0qt9b
George Washington, first President of the United States, common.image.appears_in_topic_gallery, Presidency of George Washington
President of the United States, government.government_office_or_title.office_holders, m.03q2h_9
Presidential Command: Power, Leadership, and the Making of Foreign Policy from Richard Nixon to George W. Bush, book.written_work.subjects, President of the United States
m.03fx83v, government.government_position_held.office_position_or_title, President of the United States
President of the United States, government.government_office_or_title.office_holders, m.01xrx8q
William Howard Taft, people.person.nationality, United States of America
President of the United States, government.government_office_or_title.office_holders, m.03fx838
President of the United States, common.topic.notable_for, g.125734vfj
United States of America, people.person.nationality, Ronald Reagan
m.0446b9r, government.government_position_held.office_position_or_title, President of the United States
United States of America, government.governmental_jurisdiction.government_positions, President of the United States
Jimmy Carter, common.topic.notable_types, US President
m.0446b70, government.government_position_held.office_position_or_title, President of the United States
President of the United States, book.book_subject.works, Max for President
m.03fx8cf, government.government_position_held.office_position_or_title, President of the United States
m.02kzpyv, government.government_position_held.office_position_or_title, President of the United States
US President, type.type.expected_by, President
John Adams, people.person.nationality, United States of America
Vice President of the United States, fictional_universe.character_occupation.characters_with_this_occupation, Vice President Becker
The Reader's Companion to the American Presidency, book.book.editions, The Reader's Companion to the American Presidency
Warren G. Harding, common.topic.notable_types, US President
John F. Kennedy, freebase.valuenotation.is_reviewed, President number
US President, freebase.type_profile.published, Published
m.03fx82m, government.government_position_held.office_position_or_title, President of the United States
Lt. Cmdr. Robby Jackson, fictional_universe.fictional_character.occupation, President of the United States
m.02hz5r6, government.government_position_held.office_position_or_title, President of the United States
President of the United States, fictional_universe.character_occupation.characters_with_this_occupation, Jack Ryan
m.04469xv, government.government_position_held.office_position_or_title, President of the United States
President of the United States, book.book_subject.works, First Off the Tee: Presidential Hackers, Duffers, and Cheaters From Taft to Bush
President of the United States, common.topic.webpage, m.09w6h41
James Monroe, common.topic.notable_types, US President
m.0hnjbwk, common.webpage.topic, President of the United States
President of the United States, common.topic.webpage, m.0b46f7h
Ronald Reagan, common.topic.notable_types, US President
John Tyler, common.topic.notable_types, US President
Thomas Jefferson, common.topic.notable_types, US President
m.02k6vpl, government.government_position_held.office_position_or_title, President of the United States
President of the United States, book.book_subject.works, The American Leadership Tradition: Moral Vision from Washington to Clinton
Franklin D. Roosevelt, people.person.nationality, United States of America
President of the United States, business.employer.employees, m.0whvvj4
John Quincy Adams, common.topic.notable_types, US President
John Quincy Adams, people.person.nationality, United States of America
President of the United States, book.book_subject.works, The Moral Rhetoric of American Presidents
m.03fx81_, government.government_position_held.office_position_or_title, President of the United States
George Washington, first President of the United States, common.image.size, m.02f0j1t
President of the United States, government.government_office_or_title.office_holders, m.0446b9r
President of the United States, award.award_presenting_organization.awards_presented, National Medal of Technology and Innovation
President of the United States, government.government_office_or_title.office_holders, m.0446bdk
President of the United States, government.government_office_or_title.office_holders, m.04466xb
m.04466xz, government.government_position_held.office_position_or_title, President of the United States
Mackenzie Allen, fictional_universe.fictional_character.occupation, President of the United States
Andrew Johnson, common.topic.notable_types, US President
President of the United States, common.topic.webpage, m.09xgz2n
Andrew Jackson, government.us_president.vice_president, Martin Van Buren
George Washington, first President of the United States, common.image.appears_in_topic_gallery, Powers of the President of the United States
John F. Kennedy, people.person.nationality, United States of America
Grace for President, book.written_work.subjects, President of the United States
President of the United States, government.government_office_or_title.office_holders, m.03fx7_v
m.09y9g34, common.webpage.topic, President of the United States
Dwight D. Eisenhower, people.person.nationality, United States of America
Andrew Jackson, common.topic.notable_types, US President
Grover Cleveland, common.topic.notable_types, US President
President of the United States, government.government_office_or_title.office_holders, m.04469yh
President of the United States, fictional_universe.character_occupation.characters_with_this_occupation, Mackenzie Allen
m.04466zr, government.government_position_held.office_position_or_title, President of the United States
James Buchanan, people.person.nationality, United States of America
John F. Kennedy, common.topic.notable_types, US President
Theodore Roosevelt, people.person.nationality, United States of America
m.03fx87q, government.government_position_held.office_position_or_title, President of the United States
Abraham Lincoln, government.us_president.vice_president, Andrew Johnson
Andrew Johnson, government.us_vice_president.to_president, Abraham Lincoln
Alan Brinkley, book.author.works_edited, The Reader's Companion to the American Presidency
Vice President of the United States, freebase.valuenotation.has_no_value, Governmental body (if any)
US President, freebase.type_profile.kind, Title
President of the United States, common.topic.webpage, m.04lsvx0
m.04wrwjv, base.firsts.first_achievement.achievement, President of the United States
President of the United States, government.government_office_or_title.office_holders, m.03fx88b
President of the United States, base.ontologies.ontology_class.equivalent_classes, m.0dj2gvv
President of the United States, book.book_subject.works, Grace for President
m.0446b9j, government.government_position_held.office_position_or_title, President of the United States
President of the United States, government.government_office_or_title.office_holders, m.03fx8bt
President of the United States, base.firsts.achievement.firsts, m.04xdfjz
US President, common.topic.notable_types, Ronald Reagan
m.01xrx8q, government.government_position_held.office_position_or_title, President of the United States
Thomas Jefferson, people.person.nationality, United States of America
Presidential Command: Power, Leadership, and the Making of Foreign Policy from Richard Nixon to George W. Bush, common.topic.article, m.063t8my

Answer: Ronald Reagan