Question: What is the least popular official language in the country where a spiral viaduct is located in Karin Thomas' birthplace?

full_context: Document 1: Switzerland: Three of Europe's major languages are official in Switzerland. Swiss culture is characterised by diversity, which is reflected in a wide range of traditional customs. A region may be in some ways strongly culturally connected to the neighbouring country that shares its language, the country itself being rooted in western European culture. The linguistically isolated Romansh culture in Graubünden in eastern Switzerland constitutes an exception, it survives only in the upper valleys of the Rhine and the Inn and strives to maintain its rare linguistic tradition.
Document 2: Věra Klimková: Věra Klimková (born Věra Leskovjanská on 11 August 1957 in Spišská Nová Ves) was a Czechoslovakian cross country skier who competed from 1982 to 1988. She finished seventh in the 4 × 5 km relay at the 1988 Winter Olympics in Calgary.
Document 3: Karolína Grohová: Grohová competed at the 2014 Winter Olympics for the Czech Republic. She placed 38th in the qualifying round in the sprint, failing to advance to the knockout stages. She also competed with Eva Vrabcová-Nývltová, Petra Nováková and Klára Moravcová in the relay, finishing 10th.
Document 4: Alps: Crossing the Italian-Austrian border, the Brenner Pass separates the Ötztal Alps and Zillertal Alps and has been in use as a trading route since the 14th century. The lowest of the Alpine passes at 985 m (3,232 ft), the Semmering crosses from Lower Austria to Styria; since the 12th century when a hospice was built there it has seen continuous use. A railroad with a tunnel 1 mile (1.6 km) long was built along the route of the pass in the mid-19th century. With a summit of 2,469 m (8,100 ft), the Great St. Bernard Pass is one of the highest in the Alps, crossing the Italian-Swiss border east of the Pennine Alps along the flanks of Mont Blanc. The pass was used by Napoleon Bonaparte to cross 40,000 troops in 1800. The Saint Gotthard Pass crosses from Central Switzerland to Ticino; in the late 19th century the 14 km (9 mi) long Saint Gotthard Tunnel was built connecting Lucerne in Switzerland, with Milan in Italy. The Mont Cenis pass has been a major commercial road between Western Europe and Italy. Now the pass has been supplanted by the Fréjus Road and Rail tunnel. At 2,756 m (9,042 ft), the Stelvio Pass in northern Italy is one of the highest of the Alpine passes; the road was built in the 1820s. The highest pass in the alps is the col de l'Iseran in Savoy (France) at 2,770 m (9,088 ft).
Document 5: Karin Thomas: Karin Thomas (born 3 October 1961 in Brusio) was a Swiss cross country skier who competed from 1982 to 1988. She finished sixth in the 4 x 5 km relay at the 1984 Winter Olympics in Sarajevo and fourth in that same event at the 1988 Winter Olympics in Calgary.
Document 6: Glenfinnan Viaduct: The Glenfinnan Viaduct is a railway viaduct on the West Highland Line in Glenfinnan, Inverness-shire, Scotland. Located at the top of Loch Shiel in the West Highlands of Scotland, the viaduct overlooks the Glenfinnan Monument and the waters of Loch Shiel.
Document 7: Brusio spiral viaduct: The Brusio spiral viaduct (or Brusio circular viaduct; Italian: Viadotto elicoidale di Brusio, German: Kreisviadukt Brusio) is a single-track nine-arched stone spiral railway viaduct.
Document 8: Säntis: At 2,501.9 metres above sea level, Säntis is the highest mountain in the Alpstein massif of northeastern Switzerland. It is also the culminating point of the whole Appenzell Alps, between Lake Walen and Lake Constance. Shared by three cantons, the mountain is a highly visible landmark thanks to its exposed northerly position within the Alpstein massif. As a consequence, houses called "Säntisblick" (English: "Säntis view") can be found in regions as far away as the Black Forest in Germany. Säntis is among the most prominent summits in the Alps and the most prominent summit in Europe with an observation deck on the top. The panorama from the summit is spectacular. Six countries can be seen if the weather allows: Switzerland, Germany, Austria, Liechtenstein, France, and Italy.
Document 9: Switzerland: Aside from the official forms of their respective languages, the four linguistic regions of Switzerland also have their local dialectal forms. The role played by dialects in each linguistic region varies dramatically: in the German-speaking regions, Swiss German dialects have become ever more prevalent since the second half of the 20th century, especially in the media, such as radio and television, and are used as an everyday language, while the Swiss variety of Standard German is almost always used instead of dialect for written communication (c.f. diglossic usage of a language). Conversely, in the French-speaking regions the local dialects have almost disappeared (only 6.3% of the population of Valais, 3.9% of Fribourg, and 3.1% of Jura still spoke dialects at the end of the 20th century), while in the Italian-speaking regions dialects are mostly limited to family settings and casual conversation.
Document 10: Anna-Karin Hesse: Anna-Karin Hesse (1 August 1961 – 14 July 1983) was a Swedish alpine skier who competed in the 1980 Winter Olympics.
Document 11: List of territorial entities where German is an official language: Country Population 2014 / 2015 Speakers Notes (native) (second) Germany 81,083,600 74,430,000 (91.8%) 5,600,000 (6.9%) Sole nationwide official language Belgium 11,245,629 73,000 (0.6%) 2,472,746 (22%) De jure nationwide co-official language (majority language only in German speaking community) Austria 8,602,112 7,999,964 (93%) 516,000 (6%) De jure sole nationwide official language Switzerland 8,256,000 5,329,393 (64.6%) 395,000 (5%) Co-official language at federal level; de jure sole official language in 17, co-official in 4 cantons (out of 26) Luxembourg 562,958 11,000 (2%) 380,000 (67.5%) De jure nationwide co-official language Liechtenstein 37,370 32,075 (85.8%) 5,200 (13.9%) De jure sole nationwide official language Total 109,787,669 87,875,432 9,368,946 Total speakers: 97,244,378
Document 12: Tomass Dukurs: His younger brother Martins is also a skeleton racer. Both he and his brother made the 2010 Winter Olympics and the 2014 Winter Olympics.
Document 13: Dialect: The situation in Switzerland and Liechtenstein is different from the rest of the German-speaking countries. The Swiss German dialects are the default everyday language in virtually every situation, whereas standard German is seldom spoken. Some Swiss German speakers perceive standard German to be a foreign language.
Document 14: Brusio spiral viaduct: A signature structure of the World Heritage-listed Bernina railway, it is located near Brusio, in the Canton of Graubünden, Switzerland, and was built to limit the railway's gradient at that location within its specified maximum of 7%.
Document 15: Switzerland: Switzerland has four official languages: principally German (63.5% total population share, with foreign residents, in 2013); French (22.5%) in the west; and Italian (8.1%) in the south. The fourth official language, Romansh (0.5%), is a Romance language spoken locally in the southeastern trilingual canton of Graubünden, and is designated by Article 4 of the Federal Constitution as a national language along with German, French, and Italian, and in Article 70 as an official language if the authorities communicate with persons who speak Romansh. However, federal laws and other official acts do not need to be decreed in Romansh.
ground_truth: Romansh
sub_queries: Karin Thomas >> place of birth Answer: Brusio
Brusio spiral viaduct >> country Answer: Switzerland
What is the least popular official language of Switzerland ? Answer: Romansh