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

### Instruction:
For the 2013 completion schedule, what is the total S.no.?

### Inputs:
table_name: table, columns: ['S.no.', 'Power Plant', 'State', 'Total Capacity (MW)', 'Completion Schedule']

### Response:
SELECT SUM S.no. FROM table WHERE Completion Schedule = 2013