Question: What is the area of this region of Central Europe located mostly in Poland, in which Złotniki Lubańskie was formerly part of the historic Upper Lusatia region at its border?
{'answer': '40,000 km2', 'supporting_facts': [['Złotniki Lubańskie', 0], ['Złotniki Lubańskie', 1], ['Silesia', 0], ['Silesia', 1]]}