instruction: What is the description of the type of the company who concluded its contracts most recently?
response: SELECT T1.company_name FROM third_party_companies AS T1 JOIN maintenance_contracts AS T2 ON T1.company_id = T2.maintenance_contract_company_id JOIN Ref_Company_Types AS T3 ON T1.company_type_code = T3.company_type_code ORDER BY T2.contract_end_date DESC LIMIT 1