user: Question: Which Capacity is the lowest one that has a Rank smaller than 15, and a City of Belgrade?
Columns: ['Rank', 'Stadium', 'Capacity', 'City', 'Country']
Types: ['real', 'text', 'real', 'text', 'text']
Sample row: [1.0, 'Queensland Sport and Athletics Centre', 49000.0, 'Brisbane', 'Australia']
SQL:

assistant: SELECT MIN("Capacity") FROM "Table" WHERE "Rank" < 15.0 AND "City" = 'Belgrade';