Question: What is the pyramid building, in the city where Chen lived in 2005?

full_context: Document 1: YouTube: YouTube offered the public a beta test of the site in May 2005. The first video to reach one million views was a Nike advertisement featuring Ronaldinho in September 2005. Following a $3.5 million investment from Sequoia Capital in November, the site launched officially on December 15, 2005, by which time the site was receiving 8 million views a day. The site grew rapidly, and in July 2006 the company announced that more than 65,000 new videos were being uploaded every day, and that the site was receiving 100 million video views per day. According to data published by market research company comScore, YouTube is the dominant provider of online video in the United States, with a market share of around 43% and more than 14 billion views of videos in May 2010.
Document 2: Ultima Tower: The Ultima Tower is a hypothetical supertall skyscraper, designed by American architect Eugene Tsui in 1991. It has been envisioned to be built in San Francisco, California and could accommodate up to 1 million people. With a total height of , the tower would be 2 miles tall, and comprise 500 stories if built. It is one of the tallest buildings/man-made structures ever conceived.
Document 3: Transamerica Pyramid: The Transamerica Pyramid at 600 Montgomery Street between Clay and Washington Streets in the Financial District of San Francisco, California, United States, is a 48 - story postmodern building and the second - tallest skyscraper in the San Francisco skyline. Its height will be surpassed by Salesforce Tower, currently under construction. The building no longer houses the headquarters of the Transamerica Corporation, which moved its U.S. headquarters to Baltimore, Maryland, but it is still associated with the company and is depicted in the company's logo. Designed by architect William Pereira and built by Hathaway Dinwiddie Construction Company, at 853 feet (260 m), on completion in 1972 it was the eighth - tallest building in the world.
Document 4: Prudential Tower: The Prudential Tower, also known as the Prudential Building or, colloquially, The Pru, is an International Style skyscraper in Boston, Massachusetts. The building, a part of the Prudential Center complex, currently stands as the 2nd - tallest building in Boston, behind 200 Clarendon Street, formerly the John Hancock Tower. The Prudential Tower was designed by Charles Luckman and Associates for Prudential Insurance. Completed in 1964, the building is 749 feet (228 m) tall, with 52 floors, and (as of February 2018) is tied with others as the 96th - tallest in the United States. It contains 1,200,000 sq ft (110,000 m) of commercial and retail space. Including its radio mast, the tower stands as the tallest building in Boston, rising to 907 feet (276 m) in height.
Document 5: 580 California Street: 580 California Street is a high rise office building completed in 1987 in the Financial District of San Francisco, California. The postmodern, , 23 story tower is bordered by Kearny Street and California Street, and is topped with three faceless, twelve foot tall statues, on each side of the building on the twenty-third floor. The art installation is entitled "The Corporate Goddesses" by Muriel Castanis, the late designer and creator of the sculptures.
Document 6: Salesforce Tower: Salesforce Tower, formerly known as the Transbay Tower, is a 1,070 - foot (326 m) office skyscraper under construction in the South of Market district of downtown San Francisco. It is located at 415 Mission Street between First and Fremont Streets, next to the Transbay Transit Center site. Salesforce Tower is the centerpiece of the San Francisco Transbay redevelopment plan. The plan contains a mix of office, transportation, retail, and residential uses. When completed, the tower will be the tallest in San Francisco. With a top roof height of 970 feet (296 m) and an overall height of 1,070 feet (326 m), it will be the second - tallest building west of the Mississippi River after the Wilshire Grand Center in Los Angeles.
Document 7: 1201 Third Avenue: 1201 Third Avenue (formerly Washington Mutual Tower) is a , 55-story skyscraper in Downtown Seattle, in the U.S. state of Washington. It is the second-tallest building in the city, the eighth-tallest on the West Coast of the United States, and the 74th-tallest in the United States. Developed by Wright Runstad & Company, construction began in 1986 and finished in 1988. 1201 Third Avenue was designed by Kohn Pedersen Fox Associates and The McKinley Architects. The building was the world headquarters of the financial company Washington Mutual from the building's opening until 2006, when the company moved across the street to the WaMu Center (renamed the Russell Investments Center after the bank collapsed in 2008).
Document 8: YouTube: YouTube is a global video-sharing website headquartered in San Bruno, California, United States. The service was created by three former PayPal employees in February 2005. In November 2006, it was bought by Google for US$1.65 billion. YouTube now operates as one of Google's subsidiaries. The site allows users to upload, view, rate, share, and comment on videos, and it makes use of WebM, H.264/MPEG-4 AVC, and Adobe Flash Video technology to display a wide variety of user-generated and corporate media video. Available content includes video clips, TV clips, music videos, movie trailers, and other content such as video blogging, short original videos, and educational videos.
Document 9: YouTube: According to a story that has often been repeated in the media, Hurley and Chen developed the idea for YouTube during the early months of 2005, after they had experienced difficulty sharing videos that had been shot at a dinner party at Chen's apartment in San Francisco. Karim did not attend the party and denied that it had occurred, but Chen commented that the idea that YouTube was founded after a dinner party "was probably very strengthened by marketing ideas around creating a story that was very digestible".
Document 10: YouTube: Conversely, YouTube has also allowed government to more easily engage with citizens, the White House's official YouTube channel being the seventh top news organization producer on YouTube in 2012 and in 2013 a healthcare exchange commissioned Obama impersonator Iman Crosson's YouTube music video spoof to encourage young Americans to enroll in the Affordable Care Act (Obamacare)-compliant health insurance. In February 2014, U.S. President Obama held a meeting at the White House with leading YouTube content creators to not only promote awareness of Obamacare but more generally to develop ways for government to better connect with the "YouTube Generation". Whereas YouTube's inherent ability to allow presidents to directly connect with average citizens was noted, the YouTube content creators' new media savvy was perceived necessary to better cope with the website's distracting content and fickle audience.
Document 11: YouTube: On November 6, 2013, Google implemented a new comment system that requires all YouTube users to use a Google+ account in order to comment on videos and making the comment system Google+ oriented. The changes are in large part an attempt to address the frequent criticisms of the quality and tone of YouTube comments. They give creators more power to moderate and block comments, and add new sorting mechanisms to ensure that better, more relevant discussions appear at the top. The new system restored the ability to include URLs in comments, which had previously been removed due to problems with abuse. In response, YouTube co-founder Jawed Karim posted the question "why the fuck do I need a google+ account to comment on a video?" on his YouTube channel to express his negative opinion of the change. The official YouTube announcement received 20,097 "thumbs down" votes and generated more than 32,000 comments in two days. Writing in the Newsday blog Silicon Island, Chase Melvin noted that "Google+ is nowhere near as popular a social media network as Facebook, but it's essentially being forced upon millions of YouTube users who don't want to lose their ability to comment on videos" and "Discussion forums across the Internet are already bursting with outcry against the new comment system". In the same article Melvin goes on to say:
Document 12: Houston: Centered on Post Oak Boulevard and Westheimer Road, the Uptown District boomed during the 1970s and early 1980s when a collection of mid-rise office buildings, hotels, and retail developments appeared along Interstate 610 west. Uptown became one of the most prominent instances of an edge city. The tallest building in Uptown is the 64-floor, 901-foot (275 m)-tall, Philip Johnson and John Burgee designed landmark Williams Tower (known as the Transco Tower until 1999). At the time of construction, it was believed to be the world's tallest skyscraper outside of a central business district. The new 20-story Skanska building and BBVA Compass Plaza are the newest office buildings built in Uptown after 30 years. The Uptown District is also home to buildings designed by noted architects I. M. Pei, César Pelli, and Philip Johnson. In the late 1990s and early 2000s decade, there was a mini-boom of mid-rise and high-rise residential tower construction, with several over 30 stories tall. Since 2000 more than 30 high-rise buildings have gone up in Houston; all told, 72 high-rises tower over the city, which adds up to about 8,300 units. In 2002, Uptown had more than 23 million square feet (2,100,000 m²) of office space with 16 million square feet (1,500,000 m²) of Class A office space.
Document 13: William Pereira: William Leonard Pereira (April 25, 1909 – November 13, 1985) was an American architect from Chicago, Illinois, who was noted for his futuristic designs of landmark buildings such as the Transamerica Pyramid in San Francisco. Remarkably prolific, he worked out of Los Angeles, and was known for his love of science fiction and expensive cars, but mostly for his unmistakable style of architecture, which helped define the look of mid-20th century America.
Document 14: 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 15: YouTube: Much of YouTube's revenue goes to the copyright holders of the videos. In 2010 it was reported that nearly a third of the videos with advertisements were uploaded without permission of the copyright holders. YouTube gives an option for copyright holders to locate and remove their videos or to have them continue running for revenue. In May 2013, Nintendo began enforcing its copyright ownership and claiming the advertising revenue from video creators who posted screenshots of its games. In February 2015, Nintendo agreed to share the revenue with the video creators.
ground_truth: Transamerica Pyramid
sub_queries: Where did Chen live in 2005? Answer: San Francisco
what is the pyramid building in San Francisco Answer: Transamerica Pyramid