CREATE TABLE Third_Party_Companies (company_name VARCHAR(255), company_id VARCHAR(255)); CREATE TABLE Maintenance_Contracts (maintenance_contract_company_id VARCHAR(255), contract_start_date VARCHAR(255))
Which company started the earliest the maintenance contract? Show the company name.
    
SQL: SELECT T1.company_name FROM Third_Party_Companies AS T1 JOIN Maintenance_Contracts AS T2 ON T1.company_id = T2.maintenance_contract_company_id ORDER BY T2.contract_start_date LIMIT 1