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 are the minimum and maximum membership amounts for all branches that either opened in 2011 or are located in London? | member : member_id , card_number , name , hometown , level | branch : branch_id , name , open_year , address_road , city , membership_amount | membership_register_branch : member_id , branch_id , register_year | purchase : member_id , branch_id , year , total_pounds | membership_register_branch.branch_id = branch.branch_id | membership_register_branch.member_id = member.member_id | purchase.branch_id = branch.branch_id | purchase.member_id = member.member_id | 

### Response:

select min ( _ ) , max ( _ ) from _ where _ | select min ( membership_amount ) , max ( membership_amount ) from branch where open_year = 2011 or city = 'London'