Question: Seiersberg is a former municipality in the Austrian state that has what area?
Related documents: [0]  [DOC] Styria (German: Steiermark , ] , Slovene/Croatian: "Štajerska" , Hungarian: "Stájerország" , ) is a state or "Bundesland", located in the southeast of Austria. In area it is the second largest of the nine Austrian federated states, covering 16401 km2 . It borders Slovenia and the Austrian states of Upper Austria, Lower Austria, Salzburg, Burgenland, and Carinthia. The population (as of ) was . The capital city is Graz which had 276,526 inhabitants at the beginning of 2015. [END] 
[1]  [DOC] Seiersberg is a former municipality in the district of Graz-Umgebung in the Austrian state of Styria. Since the 2015 Styria municipal structural reform, it is part of the municipality Seiersberg-Pirka. [END] 
Answer: 
16401 km2
16401 km2