user: Question: What is the minimum population of the region in which Roskilde is the largest city?
Columns: ['Danish name', 'English name', 'Seat of administration', 'Largest city', 'Population (January 1, 2008)', 'Area (km²)', 'Pop. density (per km²)']
Types: ['text', 'text', 'text', 'text', 'real', 'real', 'text']
Sample row: ['Region Hovedstaden', 'Capital Region of Denmark', 'Hillerød', 'Copenhagen', 1645825.0, 2561.0, '642.6']
SQL:

assistant: SELECT MIN("Population (January 1, 2008)") FROM "Table" WHERE "Largest city" = 'Roskilde';