Below is an instruction that describes a task, paired with an input that provides further context. Write a response that appropriately completes the request.

### Instruction:

Convert text to sql: What is the total revenue of companies started by founder? | manufacturers : code , name , headquarter , founder , revenue | products : code , name , price , manufacturer | products.manufacturer = manufacturers.code | 

### Response:

select sum ( _ ) , _ from _ group by _ | select sum ( revenue ) , founder from manufacturers group by founder