CREATE TABLE table_1784514_1 (number_of_powiats VARCHAR, capital VARCHAR)

How many powiats have mstsislaw as a capital?
SELECT number_of_powiats FROM table_1784514_1 WHERE capital = "Mstsislaw"
SELECT "number_of_powiats" FROM "table_1784514_1" WHERE "Mstsislaw" = "capital"