user: Question: How many powiats have Mstsislaw as a capital?
Columns: ['Voivodeship after 1569', 'Capital', 'Year established', 'Number of powiats', 'Area (km²) in 1590 (Lithuanian) Category:Articles with Lithuanian-language external links']
Types: ['text', 'text', 'real', 'text', 'real']
Sample row: ['Brest Litovsk Voivodeship', 'Brest', 1566.0, '2 powiats', 40600.0]
SQL:

assistant: SELECT "Number of powiats" FROM "Table" WHERE "Capital" = 'Mstsislaw';