Question: What is the main international airport in the city where the group known for "Happy to You" was formed?

full_context: Document 1: To the Sky: To the Sky is the second studio album by American singer-songwriter and producer Kevin Rudolf. It was released on June 15, 2010 in the United States by Cash Money Records, Island Records and Universal Republic Records.
Document 2: Happiness (Hurts album): Happiness is the debut studio album by English synth-pop duo Hurts. It was released on 27 August 2010 by RCA Records. It was preceded by the release of the singles "Better Than Love" on 23 May 2010 and "Wonderful Life" on 22 August 2010. Collaborators include Jonas Quant and production team The Nexus, as well as a duet with Australian singer Kylie Minogue on the song "Devotion". To promote the release of the album, the track "Happiness" was made available as a free download via Amazon.co.uk on 1 August 2010.
Document 3: Arboga Airport: Arboga Airport is an airport serving Arboga in Västmanland County, Sweden. It is a former Swedish Airforce backup base located outside of Arboga used by the Test Unit of SWAF for tests of airborne missiles. Today, the airfield is solely used by the local flying club.
Document 4: Stockholm Arlanda Airport: Stockholm Arlanda Airport (IATA: ARN, ICAO: ESSA), is an international airport located in the Sigtuna Municipality of Sweden, near the town of Märsta, 37 kilometres (23 mi) north of Stockholm and nearly 40 kilometres (25 mi) south - east of Uppsala. The airport is located within Stockholm County and the province of Uppland. It is the largest airport in Sweden and the third - largest airport in the Nordic countries. The airport is the major gateway to international air travel for large parts of Sweden. Arlanda Airport was used by close to 27 million passengers in 2017, with 21.2 million international passengers and 5.5 million domestic.
Document 5: Miike Snow: Miike Snow was formed in 2007 in Stockholm, Sweden. Band members Christian Karlsson and Pontus Winnberg were childhood friends who spent time playing in bands and working on various projects in studios throughout the city of Gothenburg. Karlsson was a former member of the Swedish hip-hop band Goldmine, who toured with The Fugees. After separate moves to Stockholm, they reunited in 2000.
Document 6: Happy to You: Happy to You is the second studio album by Swedish indie pop band Miike Snow. It was released in the United States on 13 March 2012 by Downtown Records and Universal Republic Records, and in the United Kingdom on 19 March 2012 by Columbia Records.
Document 7: Goo Goo Dolls: On May 12, 2017, Goo Goo Dolls released a five - song EP, entitled You Should Be Happy, which features 4 original songs and a re-mix of the title track, ``Boxes, ''from their last album. In support of the EP the band will be touring throughout the summer of 2017 on the`` Long Way Home'' tour with Phillip Phillips. The tour included a performance in their hometown, Buffalo, on August 12.
Document 8: Black & Blue (Miike Snow song): "Black & Blue" is a song performed by Swedish indie pop band Miike Snow. It was released as the second single from the band's 2009 self-titled debut album on 15 October 2009 through Columbia Records. The song was written by the band alongside Henrik Jonback and Juliet Richardson. Band members Christian Karlsson and Pontus Winnberg of production duo Bloodshy & Avant had conceptualized the chorus prior to forming the band with Andrew Wyatt in 2007, but saved the idea for the Miike Snow project rather than offering it to another artist. "Black & Blue" is a blue-eyed soul and electronica song that is sung in a breathy falsetto style with piano and synthesizer instrumentation.
Document 9: Arad International Airport: Arad International Airport is located west of Arad, in western Romania, in the historical region of Crișana. The airport is located only north of Timişoara Airport. Arad International Airport also has a cargo terminal, the largest and most modern in western Romania. It is located 250 km from Budapest and 300 km from Belgrad. It’s located near the border with Hungary, only 30 km from the closest point for crossing the border - Turnu and 20 km away from the closest railway point for crossing the border - Curtici. The airport also serves as the SMURD regional air ambulance base for the 5 western counties that form the region (Arad, Bihor, Timis, Hunedoara & Caras-Severin). SMURD Arad operates 1 Eurocopter EC135 converted for the air ambulance role. Arad Airport is directly connected to the A1 motorway (part of the Pan-European Corridor IV), one of the most important and heavily used motorways in Romania.
Document 10: Hartsfield–Jackson Atlanta International Airport: Hartsfield -- Jackson Atlanta International Airport (IATA: ATL, ICAO: KATL, FAA LID: ATL), also known as Atlanta Airport, Hartsfield, or Hartsfield -- Jackson, is an international airport located 7 miles (11 km) south of Atlanta's central business district, in the U.S. state of Georgia. It has been the world's busiest airport by passenger traffic since 1998; and by number of landings and take - offs from 2005 to 2013, losing that title to Chicago - O'Hare in 2014, but regaining it a year later. Hartsfield -- Jackson held its ranking as the world's busiest airport in 2012, both in passengers and number of flights, by accommodating 100 million passengers (more than 260,000 passengers daily) and 950,119 flights. Many of the nearly one million flights are domestic flights from within the United States, where the airport serves as a major hub for travel throughout the southeastern region of the country. The airport has 207 domestic and international gates. ATL covers 4,700 acres (1,902 ha) of land and has five parallel runways.
Document 11: Therapy (MiChi album): Therapy is the second major label studio album released by British-Japanese musician MiChi, to be released on 21 March 2012 by Sony Music Entertainment. The record features just six previously unheard songs, after the remaining seven were released to the public as tracks on the various singles and EPs released in the lead up to the album's release. The album continues MiChi's tradition of including another addition to the "MadNesS Vol." series, with this being the third entrant, after the two previous released on "Michi Madness" and "Up to You".
Document 12: Friends (Swedish band): Friends was a Swedish "dansband" or pop group formed in 1999 and made up of Stefan Brunzell, Tony Haglund, Kristian Hermanson, Nina Inhammar, Kim Kärnfalk and Peter Strandberg. They were put together from auditions on the reality television show Friends på turne ("Friends on Tour"), made by Bert Karlsson for TV4. The show was a success and Friends competed on Melodifestivalen 2000, reaching second place. They won Melodifestivalen 2001 with "Lyssna till ditt hjärta" and represented Sweden at the Eurovision Song Contest 2001 with the English version of the song, "Listen to Your Heartbeat" wearing sexy, tight, leather fitted clothing. Prior to the Eurovision performance, the Swedish delegation was forced to pay royalties to the team behind "Liefde is een kaartspel", an earlier Belgian entry, making the song the first admitted case of plagiarism in Eurovision history.
Document 13: Animal (Miike Snow song): "Animal" is a song performed by Swedish indie pop band Miike Snow. It was released as the first single from the band's 2009 self-titled debut album on 17 February 2009 through Columbia and Downtown Records. Written by the band alongside Henrik Jonback, "Animal" is a pop song with instrumentation provided by horns and staccato synthesizers. Lead singer Andrew Wyatt has explained that it has an ambiguous meaning; its lyrics can be interpreted as dealing with matters such as addiction, basic instincts or dissatisfaction when one's needs are not met by society.
Document 14: Swedish House Mafia discography: Swedish house music supergroup Swedish House Mafia has released two compilation albums, one live album, six singles and six music videos. The trio formed during the mid-2000s whilst touring together and assisting each other in music production, and recorded and released the single "Leave the World Behind" in 2009, although all were assigned individual artist credits for the song. The group itself rose to prominence after performing a DJ set at the Cream Amnesia nightclub in Ibiza in 2008, and were later signed by record label EMI in 2010. "Until One", a compilation album containing both their own material and mixes of songs by other artists, peaked at number 13 in Sweden and in the top ten of the album charts of The Netherlands and the Flanders region of Belgium: two singles, "One" and "Miami 2 Ibiza", both attained chart success across Europe, with the former topping the Dutch Top 40 and the latter reaching the top five of the Flanders, Irish and United Kingdom singles charts. "One" and "Miami 2 Ibiza" were certified septuple and quintuple platinum in Sweden by the International Federation of the Phonographic Industry" (IFPI).
Document 15: New Delhi: Indira Gandhi International Airport, situated to the southwest of Delhi, is the main gateway for the city's domestic and international civilian air traffic. In 2012-13, the airport was used by more than 35 million passengers, making it one of the busiest airports in South Asia. Terminal 3, which cost ₹96.8 billion (US$1.4 billion) to construct between 2007 and 2010, handles an additional 37 million passengers annually.
ground_truth: Stockholm Arlanda Airport
sub_queries: Happy to You >> performer Answer: Miike Snow
What city was Miike Snow formed in? Answer: Stockholm
what is the main international airport in Stockholm Answer: Stockholm Arlanda Airport