Below is an instruction that describes a task. Write a response that appropriately completes the request.

### Instruction:
How many different municipal mayors were there in the municipality with an area of 42.66 km2?

### Inputs:
table_name: table, columns: ['Municipality', 'Type', 'District', 'Area (km²)', 'Population (2010)', 'Pop. Density (per km²)', 'No. of Barangays', 'Municipal Mayor']

### Response:
SELECT COUNT Municipal Mayor FROM table WHERE Area (km²) = 42.66