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: Which employees have either destroyed a document or made an authorization to do so? Return their employee ids. | ref_document_types : document_type_code , document_type_name , document_type_description | ref_calendar : calendar_date , day_number | ref_locations : location_code , location_name , location_description | roles : role_code , role_name , role_description | all_documents : document_id , date_stored , document_type_code , document_name , document_description , other_details | employees : employee_id , role_code , employee_name , gender_mfu , date_of_birth , other_details | document_locations : document_id , location_code , date_in_location_from , date_in_locaton_to | documents_to_be_destroyed : document_id , destruction_authorised_by_employee_id , destroyed_by_employee_id , planned_destruction_date , actual_destruction_date , other_details | all_documents.date_stored = ref_calendar.calendar_date | all_documents.document_type_code = ref_document_types.document_type_code | employees.role_code = roles.role_code | document_locations.document_id = all_documents.document_id | document_locations.date_in_locaton_to = ref_calendar.calendar_date | document_locations.date_in_location_from = ref_calendar.calendar_date | document_locations.location_code = ref_locations.location_code | documents_to_be_destroyed.document_id = all_documents.document_id | documents_to_be_destroyed.actual_destruction_date = ref_calendar.calendar_date | documents_to_be_destroyed.planned_destruction_date = ref_calendar.calendar_date | documents_to_be_destroyed.destruction_authorised_by_employee_id = employees.employee_id | documents_to_be_destroyed.destroyed_by_employee_id = employees.employee_id | 

### Response:

select _ from _ union select _ from _ | select destroyed_by_employee_id from documents_to_be_destroyed union select destruction_authorised_by_employee_id from documents_to_be_destroyed