user: Question: How many different municipal mayors were there in the municipality with an area of 42.66 km2?
Columns: ['Municipality', 'Type', 'District', 'Area (km²)', 'Population (2010)', 'Pop. Density (per km²)', 'No. of Barangays', 'Municipal Mayor']
Types: ['text', 'text', 'text', 'text', 'real', 'text', 'real', 'text']
Sample row: ['Alaminos', '3rd Class', '3rd District', '57.46', 43526.0, '757.5', 15.0, 'Eladio Magampon']
SQL:

assistant: SELECT COUNT("Municipal Mayor") FROM "Table" WHERE "Area (km²)" = '42.66';