Question: How many of the restaurants with the lowest risk level failed the complaint inspection type?
SQL: SELECT COUNT(DISTINCT T1.license_no) FROM establishment AS T1 INNER JOIN inspection AS T2 ON T1.license_no = T2.license_no WHERE T1.risk_level = '1' AND T2.inspection_type = 'Complaint' AND T1.facility_type = 'Restaurant' AND T2.results = 'Fail'