Question: Where is the headquarter of the Coop Extra?

full_context: Document 1: Coop (Hungary): Coop is a Hungarian supermarket chain and buying group with about 4000 stores. In 2015, it is the second largest retail chain in Hungary.
Document 2: Norwegian Confederation of Trade Unions: The Norwegian Confederation of Trade Unions (Norwegian: "Landsorganisasjonen i Norge" , LO) is a national trade union center, decidedly the largest and probably the most influential umbrella organization of labour unions in Norway. The 21 national unions affiliated to the LO have almost 900,000 members of a Norwegian population of 5 million. The majority of affiliated unions organizes traditional blue collar workers, but the largest affiliate is the Norwegian Union of Municipal and General Employees which makes up more than a third of all members. LO is affiliated to the ITUC and the ETUC. Gerd Kristiansen was elected leader on 6 May 2013 for a four-year period.
Document 3: Associated Food Stores: Associated Food Stores is an American retailers cooperative that supplies about 500 independently owned retail supermarkets throughout Utah, Arizona, Idaho, Colorado, Montana, Oregon, Nevada, and Wyoming.
Document 4: Edeka: The Edeka Group is the largest German supermarket corporation, currently holding a market share of 26%. Founded in 1898, it consists today of several cooperatives of independent supermarkets all operating under the umbrella organisation "Edeka Zentrale AG & Co KG", with headquarters in Hamburg. There are approximately 4,100 stores with the Edeka nameplate that range from small corner stores to hypermarkets. On November 16, 2007, Edeka reached an agreement with Tengelmann (known for A&P in the US) to purchase a 70% majority stake in Tengelmann's Plus discounter store division.
Document 5: Federated Co-operatives: Federated Co-operatives Limited (FCL), is a co-operative federation, established in 1955, providing procurement and distribution to member co-operatives in Western Canada. Federated Co-operatives is owned by about 365 member co-operatives across the region. Some are large co-operatives, such as Saskatoon Co-op and Calgary Co-op, while others are small co-ops based in small towns, such as Abernethy Co-op.
Document 6: Warehouse store: A warehouse store or warehouse supermarket is a food and grocery retailer that operates stores geared toward offering deeper discounted prices than a traditional supermarket. These stores offer a no-frills experience and warehouse shelving stocked well with merchandise intended to move at higher volumes. Unlike warehouse clubs, warehouse stores do not require a membership or membership fees. Warehouse stores also offer a selection of merchandise sold in bulk, Typically warehouse stores are laid out in a logical format which leads people a certain way around the store to the checkout. As one enters the store they are directed down an aisle of discounted special buys when entering the store. From there the layout typically then leads to the fresh Produce followed by the Deli at the back of the store. Also included bakery and other departments similar to other supermarkets. Another typical feature of these stores is that the customer bags their own groceries which also helps to reduce the overall cost. Many warehouse stores are operated by traditional grocery chains both as a way to attract lower income, value conscious consumers and to maximize their buying power in order to lower costs at their mainstream stores. Notable examples of corporations who operate warehouse stores include United States chains Kroger and Albertsons LLC and the smaller Sacramento-based Nugget Market. However, WinCo Foods is an exception as it is a warehouse chain of its own and not part of a larger chain of traditional supermarkets like A&P, Safeway, Kroger, or Supervalu.
Document 7: The Co-operative Group: The Co-operative Group, trading as The Co-op, is a British consumer co-operative with a diverse family of retail businesses including food retail; electrical retail; financial services; insurance services; legal services and funeralcare, with in excess of 4,200 locations. It is the largest consumer co-operative in the UK and owned by more than 4 million active members. Membership is open to everyone aged 16 and over in the society, provided they agree to subscribe £1 sterling in the capital of the society out of their first share of the profits and share the values & principles upon which the group was founded. Members are democratically involved in setting business strategy, decide how social goals are achieved, and share in its profits - in the 2016 £19m was returned to members and their chosen local community causes via the 5+1 scheme. No year end dividend was paid in 2015.
Document 8: Extra (Coop): Extra is a Norwegian discount supermarket chain of around 340 stores. It is part of the Coop Norge cooperative and was until late 2015 named Coop Extra. The chain markets itself as being low-cost while maintaining large stores with a wide selection of items.
Document 9: Coop Norge: Coop Norge SA is a Norwegian cooperative. It is owned by 117 local cooperatives with more than 1.3 million members. The company has its headquarters in Oslo.
Document 10: Universal Cooperatives: Universal Cooperatives, based in Eagan, Minnesota, is a cooperative controlled by 17 regional agricultural marketing and agricultural supply cooperatives. The distribution system includes 110 regional feed mills, 26 warehouses, and 7 research farms. The company was formed November 1, 1972 by a merger of United Cooperatives, Inc. of Alliance, Ohio and National Cooperatives, Inc. of Albert Lea, Minnesota. The companies had inter-mixed ownership, leading to merger discussion, and eventual merger. On May 11, 2014, Universal Cooperatives, Inc. and its domestic subsidiaries filed for voluntary Chapter 11 bankruptcy.
Document 11: Netto Marken-Discount: Netto Marken-Discount is a German supermarket chain. It is owned by the largest German supermarket cooperative Edeka Group and operates mostly in the south and west of Germany. The first store was opened in 1984 and the chain is expanding aggressively, with its 1000th store opening in 2004 and its 4000th in 2009.
Document 12: Coles Supermarkets: Coles Supermarkets Australia Pty Ltd, trading as Coles, is an Australian supermarket chain owned by Wesfarmers.
Document 13: Dansk Supermarked: Dansk Supermarked A/S (Danish Supermarket Ltd) is Denmark's largest retailer, with a market share of 34.9%. It owns several chains of stores - Netto, Føtex, Bilka and Salling. All of these chains operate exclusively in Denmark except Netto, which has expanded into Germany, Poland, Sweden and has made two unsuccessful attempts at operating in the United Kingdom.
Document 14: Coop (Italy): Coop is a system of Italian consumers' cooperatives which operates the largest supermarket chain in Italy. Its headquarters are located in Casalecchio di Reno, Province of Bologna.
Document 15: Coop Prix: Coop Prix is a chain of 315 discount stores throughout Norway managed by Coop Norge and owned by local cooperatives. The chain was created in 1990 for the cooperatives to be able to compete with other discount stores like REMA 1000 and RIMI.
ground_truth: Oslo