Question: Where is the headquarters of the company through which viewers can vote for a contestant using Fan Save?

full_context: Document 1: American Idol: From the semi-finals onwards, the fate of the contestants is decided by public vote. During the contestant's performance as well as the recap at the end, a toll-free telephone number for each contestant is displayed on the screen. For a two-hour period after the episode ends (up to four hours for the finale) in each US time zone, viewers may call or send a text message to their preferred contestant's telephone number, and each call or text message is registered as a vote for that contestant. Viewers are allowed to vote as many times as they can within the two-hour voting window. However, the show reserves the right to discard votes by power dialers. One or more of the least popular contestants may be eliminated in successive weeks until a winner emerges. Over 110 million votes were cast in the first season, and by season ten the seasonal total had increased to nearly 750 million. Voting via text messaging was made available in the second season when AT&T Wireless joined as a sponsor of the show, and 7.5 million text messages were sent to American Idol that season. The number of text messages rapidly increased, reaching 178 million texts by season eight. Online voting was offered for the first time in season ten. The votes are counted and verified by Telescope Inc.
Document 2: Hidden Cash: On May 22, 2014, Hidden Cash began hiding money in San Francisco, California and tweeting out clues using the handle. Followers are encouraged to tweet a photo of themselves with the money they find, and Hidden Cash retweets these. Within a week, the group expanded to Los Angeles, and the account gained national and international media attention, and hundreds of thousands of followers.
Document 3: American Idol: This was the first season where the contestants were permitted to perform in the final rounds songs they wrote themselves. In the Top 8, Sam Woolf received the fewest votes, but he was saved from elimination by the judges. The 500th episode of the series was the Top 3 performance night.
Document 4: American Idol: Voting results have been a consistent source of controversy. The mechanism of voting had also aroused considerable criticisms, most notably in season two when Ruben Studdard beat Clay Aiken in a close vote, and in season eight, when the massive increase in text votes (100 million more text votes than season 7) fueled the texting controversy. Concerns about power voting have been expressed from the very first season. Since 2004, votes also have been affected to a limited degree by online communities such as DialIdol, Vote for the Worst (closed in 2013), and Vote for the Girls (started 2010).
Document 5: 2008 Summer Olympics torch relay: Some advocates for Tibet, Darfur, and the spiritual practice Falun Gong, planned to protest the April 9 arrival of the torch in San Francisco. China had already requested the torch route in San Francisco be shortened. On April 7, 2008, two days prior to the actual torch relay, three activists carrying Tibetan flags scaled the suspension cables of the Golden Gate Bridge to unfurl two banners, one saying "One World, One Dream. Free Tibet", and the other, "Free Tibet '08". Among them was San Francisco resident Laurel Sutherlin, who spoke to the local TV station KPIX-CBS5 live from a cellphone, urging the International Olympic Committee to ask China not to allow the torch to go through Tibet. "Sutherlin said he was worried that the torch's planned route through Tibet would lead to more arrests and Chinese officials would use force to stifle dissent." The three activists and five supporters face charges related to trespassing, conspiracy and causing a public nuisance.
Document 6: Now You See Me (film): A year later, the four have their first major performance as the Four Horsemen in an elaborate Las Vegas show funded by insurance magnate Arthur Tressler (Michael Caine). Their final trick appears to transport one of the audience members to the vault of his bank, the Crédit Républicain in Paris, where stacks of new euro bills are stored. At the magicians' command, the fans in the vault activate, drawing the bills into the vents and then showering the Las Vegas crowd with them. The euros are shown to be real, and the vault in Paris is found to be empty of its recent shipment of euros. FBI agent Dylan Rhodes (Mark Ruffalo), and Interpol agent Alma Dray (Mélanie Laurent), are then partnered to investigate the Horsemen. The two question the magicians but have no evidence to hold them. Dylan and Alma turn to Thaddeus Bradley (Morgan Freeman), a former magician who now makes money by explaining the tricks behind magic acts. Thaddeus demonstrates how the Horsemen used a mock vault under the Las Vegas stage and says that the group must have stolen the money in Paris before it arrived at the bank, replacing it with flash paper that left no evidence.
Document 7: American Idol: The two finalists were Kris Allen and Adam Lambert, both of whom had previously landed in the bottom three at the top five. Allen won the contest in the most controversial voting result since season two. It was claimed, later retracted, that 38 million of the 100 million votes cast on the night came from Allen's home state of Arkansas alone, and that AT&T employees unfairly influenced the votes by giving lessons on power-texting at viewing parties in Arkansas.
Document 8: American Idol: The "Fan Save" was introduced in the fourteenth season. During the finals, viewers are given a five-minute window to vote for the contestants in danger of elimination by using their Twitter account to decide which contestant will move on to the next show, starting with the Top 8.
Document 9: Into the Gauntlet: "Into the Gauntlet" begins as Amy and Dan Cahill enter a London hotel tired and with no lead whatsoever. They receive another lead, but this is stolen by Isabel Kabra via a pet monkey, who leaves them a coin with a fancy script K on it. However, Dan, who has already memorized it, rewrites it. Amy looks all over the Internet to find out what it means, and she is about to shout out when Nellie realizes that the Kabra coin is a bug. She destroys it, along with three other bugs from each of the other three branches. Amy then tells them that the clue leads to William Shakespeare, so they go to a performance of Romeo and Juliet in The Globe Theatre. Once there, they confront the Starlings, who are back in the clue hunt after being sent to the hospital in an explosion back in "The Maze of Bones", and steal their lead, but they are trapped by Jonah Wizard, who was forced back into the clue hunt by Cora Wizard, the Holts, Alistair Oh, and the Kabras. Hamilton Holt steals the piece of paper with the lead, but Dan rips off the top and bottom, and he and Amy run away while everyone else is fighting over the rest of the lead. Their section of the lead says: "For this great man we sing was b here". The rest of the word that goes with the letter "b" was torn off, so they assume that it was supposed to be "born".
Document 10: Ryan Lackey: Lackey returned to the US and located in San Francisco where he worked for a number of start-up companies before applying to Y Combinator. He was accepted into Y Combinator's Summer 2011 round. Lackey founded CryptoSeal, a VPN as a service start-up with a small group of people well known in the computer security community, and secured funding from Ron Conway and a well known venture capital fund. In June 2014, CryptoSeal was acquired by CloudFlare.
Document 11: @ANCAlerts: @ANCAlerts (stylized as @ancalerts) is a social media news program of ABS-CBN News Channel in the Philippines which started from ANC’s influential Twitter account that has over 450,000 followers to date, aimed to keep viewers abreast of the hottest social media buzz, user-generated content, “Bayan Mo, iPatrol Mo” stories, and real time feedback from ANC viewers. Airs Weekdays at 5:00 p.m. and anchored by social media enthusiasts Lexi Schulze.
Document 12: American Idol: The most popular contestants are usually not revealed in the results show. Instead, typically the three contestants (two in later rounds) who received the lowest number of votes are called to the center of the stage. One of these three is usually sent to safety; however the two remaining are not necessarily the bottom two. The contestant with the fewest votes is then revealed and eliminated from the competition. A montage of the eliminated contestant's time on the show is played and they give their final performance. However, in season six, during the series' first ever Idol Gives Back episode, no contestant was eliminated, but on the following week, two were sent home. Moreover, starting in season eight, the judges may overturn viewers' decision with a "Judges' Save" if they unanimously agree to. "The save" can only be used once, and only up through the top five. In the eighth, ninth, tenth, and fourteenth seasons, a double elimination then took place in the week following the activation of the save, but in the eleventh and thirteenth seasons, a regular single elimination took place. The save was not activated in the twelfth season and consequently, a non-elimination took place in the week after its expiration with the votes then carrying over into the following week.
Document 13: Pokémon Go: At Comic - Con 2016, John Hanke, founder of Niantic, revealed the appearances of the three team leaders: Candela (Team Valor), Blanche (Team Mystic), and Spark (Team Instinct). Hanke conveyed that approximately 10% of the ideas for the game were implemented. Future updates, including the addition of trading, more Pokémon, implementation of Pokémon Centers at PokéStops, a patch for the ``three step glitch '', and easier training, were also confirmed. He also stated that Niantic would be continuing support for the game for`` years to come''. In an interview with TechCrunch in September 2016, Hanke hinted that player vs. player Pokémon battles would be released in a future update. In December 2016, coffeehouse chain Starbucks and telecommunications company Sprint collaborated with Nintendo to add PokéStops and gyms at certain locations of theirs throughout the United States. That same month, a companion app for Apple Watch devices was released, which allows users to receive notifications about nearby Pokémon, but does not allow for them to be caught. In January 2017, an additional 5,000 more Starbucks locations became available as gyms. In February 2017, an update was released which introduced over 100 species based in the Johto region from the second generation of the core Pokémon series, which were added alongside the original 151. The update also included the addition of new berries, new Pokémon encounter mechanics, and an expanded selection of avatar clothing options. Some of the Pokémon introduced in Ruby and Sapphire were added in late 2017, starting with a Halloween event in October and 50 more in December. A weather system was added alongside the latter, allowing real - world weather to affect gameplay.
Document 14: American Idol: The wildcard round returned in season eight, wherein there were three groups of twelve, with three contestants moving forward – the highest male, the highest female, and the next highest-placed singer - for each night, and four wildcards were chosen by the judges to produce a final 13. Starting season ten, the girls and boys perform on separate nights. In seasons ten and eleven, five of each gender were chosen, and three wildcards were chosen by the judges to form a final 13. In season twelve, the top twenty semifinalists were split into gender groups, with five of each gender advancing to form the final 10. In season thirteen, there were thirty semifinalists, but only twenty semifinalists (ten for each gender) were chosen by the judges to perform on the live shows, with five in each gender and three wildcards chosen by the judges composing the final 13.
Document 15: American Idol: Jessica Sanchez received the fewest number of votes during the Top 7 week, and the judges decided to use their "save" option on her, making her the first female recipient of the save. The following week, unlike previous seasons, Colton Dixon was the only contestant sent home. Sanchez later made the final two, the first season where a recipient of the save reached the finale.
ground_truth: San Francisco
sub_queries: How do viewers vote for a contestant using Fan Save? Answer: Twitter
Twitter >> headquarters location Answer: San Francisco