Question: What is the undergraduate enrollment at the alma mater of the Delivering Happiness author?

full_context: Document 1: Harvard University: The Harvard Business School and many of the university's athletics facilities, including Harvard Stadium, are located on a 358-acre (145 ha) campus opposite the Cambridge campus in Allston. The John W. Weeks Bridge is a pedestrian bridge over the Charles River connecting both campuses. The Harvard Medical School, Harvard School of Dental Medicine, and the Harvard School of Public Health are located on a 21-acre (8.5 ha) campus in the Longwood Medical and Academic Area approximately 3.3 miles (5.3 km) southwest of downtown Boston and 3.3 miles (5.3 km) south of the Cambridge campus.
Document 2: Steve Chen: Chen was an employee at PayPal, where he first met Chad Hurley and Jawed Karim. Chen was also an early employee at Facebook, although he left after several months to start YouTube.In 2005, Chad Hurley, Jawed Karim and Chen founded YouTube, with Chen having the position of chief technology officer. In June 2006, Chen was named by Business 2.0 as one of "The 50 people who matter now" in business.On October 16, 2006, Chen and Hurley sold YouTube to Google, Inc. for $1.65 billion. Chen received 625,366 shares of Google and an additional 68,721 in a trust as part of the sale. As of 2018, the Google shares are valued at $729 million.He and Hurley started AVOS Systems which acquired Delicious from Yahoo! Inc.
Document 3: Fred Mossler: Fred Mossler (born July 2, 1966 in San Francisco, CA) is a business executive, fashion guru, and philanthropist. He is best known as a former high-ranking executive at online shoe retailer Zappos, where he played a significant role in the company’s growth, as well as being the founder of Las Vegas-centric investment fund Honus Capital, LLC and co-founder of luxury fashion brand Ross and Snow.
Document 4: Delivering Happiness: Delivering Happiness (2010) is a book by Zappos CEO Tony Hsieh. It details his life as an entrepreneur, with emphasis on the founding of LinkExchange and Zappos.
Document 5: Admerasia: Admerasia was founded in 1993 by Zan Ng, a commercial photographer. He began the company with a personal investment of $250,000 that he and his brothers had saved up. In 1994, advertising executive Joseph Liu joined the company as a partner. Liu previously owned his own advertising company but joined Admerasia as he no longer wanted to deal with the risks associated with entrepreneurship. Both Ng and Liu came to the United States in 1975 in hopes of finding work as artists, Ng without any possessions and Liu with only a rice cooker.
Document 6: LinkExchange: It was founded in March 1996 by 23-year-old Harvard graduates Tony Hsieh (who later went on to invest in and become the CEO of Zappos) and Sanjay Madan. Ali Partovi later joined them as a third partner in August 1996. In November 1996, when the company consisted of about 10 people, it moved from Hsieh's and Madan's living room to an office in San Francisco. In May 1997, the company received US$3 million in funding from Sequoia Capital.
Document 7: I'm Feeling Lucky (book): I'm Feeling Lucky: The Confessions of Google Employee Number 59 is a 2011 book by Douglas Edwards, who was Google's first director of marketing and brand management. The book tells his story of what it was to be on the inside during the rise of one of the most powerful internet companies from its start-up beginnings.
Document 8: Reid Hoffman: Hoffman co-founded LinkedIn in December 2002 with two former colleagues from SocialNet (including Allen Blue), a former college classmate and a former colleague from his time at Fujitsu. It launched on May 5, 2003, as one of the first business-oriented online social networks. Peter Thiel and Keith Rabois, colleagues of Hoffman's at PayPal, invested in LinkedIn. By November 2014, LinkedIn had over 332 million members in more than 200 countries and territories. The site allows registered users to create professional profiles and connect with each other. Users can invite anyone (whether a site user or not) to become a connection. According to Forbes, "LinkedIn is, far and away, the most advantageous social networking tool available to job seekers and business professionals today."Hoffman was LinkedIn's founding CEO for the first four years before becoming chairman and president of products in February 2007. He became executive chairman in June 2009. With the IPO of LinkedIn on May 19, 2011, Hoffman owns a stake worth an estimated $2.34 billion, not including any potential benefits from Greylock Partners, where he was named a partner in 2009. Hoffman believes that many people still do not know how to use its service and it is LinkedIn's job to help them out. In an interview, Hoffman said that "you have to think proactively about how to use a tool that enables your ability to move in ways that you weren't able to move before, and most of people are not very good at that".Microsoft proposed to acquire LinkedIn on June 13, 2016 for $26.2 billion in cash. Hoffman became a Microsoft board member on March 14, 2017.
Document 9: Harvard University: Harvard's 2,400 professors, lecturers, and instructors instruct 7,200 undergraduates and 14,000 graduate students. The school color is crimson, which is also the name of the Harvard sports teams and the daily newspaper, The Harvard Crimson. The color was unofficially adopted (in preference to magenta) by an 1875 vote of the student body, although the association with some form of red can be traced back to 1858, when Charles William Eliot, a young graduate student who would later become Harvard's 21st and longest-serving president (1869–1909), bought red bandanas for his crew so they could more easily be distinguished by spectators at a regatta.
Document 10: ConnectU: ConnectU (originally HarvardConnection) was a social networking website launched on May 21, 2004, that was founded by Harvard students Cameron Winklevoss, Tyler Winklevoss, and Divya Narendra in December 2002. Users could add people as friends, send them messages, and update their personal profiles to notify friends about themselves. Users were placed in networks based upon the domain name associated with the email address they used for registration.
Document 11: CSS Zen Garden: In February 2005, "The Zen of CSS Design" (Peachpit Press) was published by CSS Zen Garden creator Dave Shea and web designer Molly Holzschlag. The book is based on 36 designs featured at the Zen Garden site.
Document 12: Harvard University: The Harvard Crimson competes in 42 intercollegiate sports in the NCAA Division I Ivy League. Harvard has an intense athletic rivalry with Yale University culminating in The Game, although the Harvard–Yale Regatta predates the football game. This rivalry, though, is put aside every two years when the Harvard and Yale Track and Field teams come together to compete against a combined Oxford University and Cambridge University team, a competition that is the oldest continuous international amateur competition in the world.
Document 13: Harvard University: Undergraduate admission to Harvard is characterized by the Carnegie Foundation as "more selective, lower transfer-in". Harvard College accepted 5.3% of applicants for the class of 2019, a record low and the second lowest acceptance rate among all national universities. Harvard College ended its early admissions program in 2007 as the program was believed to disadvantage low-income and under-represented minority applicants applying to selective universities, yet for the class of 2016 an Early Action program was reintroduced.
Document 14: Amazon (company): Amazon.com, Inc. Trading name Amazon Formerly Cadabra, Inc. (1994 -- 95) Type Public Traded as NASDAQ: AMZN NASDAQ - 100 component S&P 100 component S&P 500 component ISIN US0231351067 Industry Online shopping Founded July 5, 1994; 24 years ago (1994 - 07 - 05) Founder Jeff Bezos Headquarters Seattle, Washington, U.S. Area served Worldwide Key people Jeff Bezos (Chairman, President & CEO) Werner Vogels (CTO) Products Amazon Appstore Amazon Echo Amazon Kindle Amazon Prime Amazon Video ComiXology Revenue US $177.86 billion (2017) Operating income US $4.106 billion (2017) Net income US $3.033 billion (2017) Total assets US $131.31 billion (2017) Total equity US $27.709 billion (2017) Number of employees 566,000 (2017) Subsidiaries A9.com AbeBooks Alexa Internet Amazon Books Amazon Game Studios Amazon Lab126 Amazon Publishing Amazon Robotics Amazon Studios Amazon Web Services Audible Inc. Body Labs Book Depository Digital Photography Review Goodreads Graphiq Internet Movie Database Ring Souq.com Twitch.tv Whole Foods Market Woot Zappos Website www.amazon.com
Document 15: Harvard University: Established originally by the Massachusetts legislature and soon thereafter named for John Harvard (its first benefactor), Harvard is the United States' oldest institution of higher learning, and the Harvard Corporation (formally, the President and Fellows of Harvard College) is its first chartered corporation. Although never formally affiliated with any denomination, the early College primarily trained Congregationalist and Unitarian clergy. Its curriculum and student body were gradually secularized during the 18th century, and by the 19th century Harvard had emerged as the central cultural establishment among Boston elites. Following the American Civil War, President Charles W. Eliot's long tenure (1869–1909) transformed the college and affiliated professional schools into a modern research university; Harvard was a founding member of the Association of American Universities in 1900. James Bryant Conant led the university through the Great Depression and World War II and began to reform the curriculum and liberalize admissions after the war. The undergraduate college became coeducational after its 1977 merger with Radcliffe College.
ground_truth: 7,200
sub_queries: Delivering Happiness >> author Answer: Tony Hsieh
Tony Hsieh >> educated at Answer: Harvard
What is the enrollment of undergraduates at Harvard ? Answer: 7,200