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

### Instruction:
How much Area (km 2) has a Common of collegno, and a Population smaller than 50137?

### Inputs:
table_name: table, columns: ['Rank', 'Common of', 'Population', 'Area (km 2 )', 'Density (inhabitants/km 2 )', 'Altitude (mslm)']

### Response:
SELECT COUNT Area (km 2 ) FROM table WHERE Common of = collegno AND Population < 50137