Question: What city shares a border with Steffen Stranz's birthplace?

full_context: Document 1: Sweden: At 449,964 km2 (173,732 sq mi), Sweden is the 55th-largest country in the world, the 4th-largest country entirely in Europe, and the largest in Northern Europe. The lowest elevation in Sweden is in the bay of Lake Hammarsjön, near Kristianstad, at −2.41 m (−7.91 ft) below sea level. The highest point is Kebnekaise at 2,111 m (6,926 ft) above sea level.
Document 2: Gerhard Mayer: He represented his native country at the 2008 Summer Olympics in Beijing, where he ended up in 18th place in the overall-rankings. He also competed at the 2012 Summer Olympics, finishing in 24th place. Mayer is best known for winning the gold medal in the men's discus event at the 2007 Summer Universiade in Bangkok, Thailand.
Document 3: Alatsee: Alatsee is a meromictic lake in Ostallgäu, Bavaria, Germany. At an elevation of 868.0 m, its surface area is 12.00 ha. This lake supposedly holds "Hitler's gold". Many divers have died or disappeared mysteriously in this lake due to the toxicity of the organisms living in this lake. These organisms create the "blood cloud " that occurs quite abundantly throughout the year.
Document 4: Hesselberg: Hesselberg (689 m above sea level) is the highest point in Middle Franconia and the Franconian Jura and is situated 60 km south west of Nuremberg, Germany. The mountain stands isolated and far from the center of the Franconian Jura, in its southwestern border region, 4 km to the north west of Wassertrüdingen. The mountain's first recorded name was "Öselberg", which probably derived from "öder Berg" (bleak mountain). This name later changed to "Eselsberg" and finally to the current name "Hesselberg". As a butte the mountain provides an insight into Jurassic geology. It has also witnessed an eventful history, many incidents were handed down from generation to generation and these mixed with facts have become legends. Nowadays many people visit Hesselberg in order to enjoy nature and the wonderful vista. When the weather is clear the Alps 150 km away can be seen.
Document 5: Martin Strege: Martin Strege (born 21 February 1966 in Kassel) is a retired German runner who specialized in the 3000 metres steeplechase.
Document 6: Stellbergsee: Stellbergsee is a lake in Söhre, Landkreis Kassel and Schwalm-Eder-Kreis, Hesse, Germany. At an elevation of 356 m, its surface area is 0.014 km².
Document 7: Stellihorn: The Stellihorn is a mountain of the Swiss Pennine Alps, overlooking the lake of Mattmark in the canton of Valais. It lies south of Saas-Almagell in the upper valley of Saas. The north side is covered by a glacier named "Nollen Gletscher".
Document 8: Schermützelsee: The Schermützelsee is a lake in Brandenburg, Germany. It is located in the town of Buckow in the district Märkisch-Oderland northwest of Müncheberg and east of the Berlin centre. With its surface area of 1.37 km² it is the largest water in the hill country „Märkische Schweiz“ and in the Märkische Schweiz Nature Park.
Document 9: Steffen Stranz: Steffen Stranz (born 16 May 1960 in Kassel, Hessen) is a retired male judoka from Germany, who twice competed for West Germany at the Summer Olympics: 1984 and 1988.
Document 10: Steffi Jacob: Steffi Jacob (born Steffi Hanzlik on 30 September 1975 in Schmalkalden) is a German skeleton racer who has competed in the early 2000s. She won a gold medal in the inaugural women's skeleton event at the 2000 FIBT World Championships in Igls.
Document 11: Steffen Hofmann: Steffen Hofmann (born 9 September 1980 in Würzburg) is a retired German footballer, playing most of his career for SK Rapid Wien of the Austrian Bundesliga. He played as an attacking midfielder.
Document 12: Seeberg: Seeberg is a municipality in the Oberaargau administrative district in the canton of Bern in Switzerland. The lake Burgäschisee is located on the border with Aeschi. On 1 January 2016 the former municipality of Hermiswil merged into Seeberg.
Document 13: Steffen Gebhardt: Steffen Gebhardt (born 22 July 1981) is a German modern pentathlete. He competed at the 2004, 2008 and 2012 Summer Olympics.
Document 14: Stefan Gaisreiter: Stefan Gaisreiter (born 10 December 1947 in Murnau am Staffelsee) is a West German bobsledder who competed from the late 1960s to the late 1970s. He won a bronze medal in the four-man event at the 1972 Winter Olympics in Sapporo.
Document 15: Claudia Österheld: Claudia Österheld (born 8 December 1968 in Kassel) is a West Germany sprint canoer who competed in the late 1980s. At the 1988 Summer Olympics in Seoul, she finished fifth in the K-4 500 m event while being eliminated in the semifinals of the K-2 500 m event.
ground_truth: Schwalm-Eder-Kreis
sub_queries: Steffen Stranz >> place of birth Answer: Kassel
Kassel >> shares border with Answer: Schwalm-Eder-Kreis