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: Return the phone number of the customer who filed the complaint that was raised most recently. | staff : staff_id , gender , first_name , last_name , email_address , phone_number | customers : customer_id , customer_type_code , address_line_1 , address_line_2 , town_city , state , email_address , phone_number | products : product_id , parent_product_id , product_category_code , date_product_first_available , date_product_discontinued , product_name , product_description , product_price | complaints : complaint_id , product_id , customer_id , complaint_outcome_code , complaint_status_code , complaint_type_code , date_complaint_raised , date_complaint_closed , staff_id | complaints.customer_id = customers.customer_id | complaints.product_id = products.product_id | complaints.staff_id = staff.staff_id | 

### Response:

select _ from _ order by _ desc limit _ | select customers.phone_number from customers join complaints on customers.customer_id = complaints.customer_id order by complaints.date_complaint_raised desc limit 1