instruction: count the number of patients whose insurance is self pay and procedure long title is allogeneic hematopoietic stem cell transpant without purging?
response: SELECT COUNT(DISTINCT demographic.subject_id) FROM demographic INNER JOIN procedures ON demographic.hadm_id = procedures.hadm_id WHERE demographic.insurance = "Self Pay" AND procedures.long_title = "Allogeneic hematopoietic stem cell transpant without purging"