A million persons nationwide have a chronic disease. A thousand of them have a rare, severe form of the disease that is fatal, and the rest have a mild form that gives them a headache once a week. A new bioengineered drug can cure a mild case or convert a severe case to a mild case. The drug is hard to manufacture and in short supply, and a severe case requires very large doses. There is enough to treat all the severe cases or all the mild cases, but not both. How should the drug be allocated to satisfy Rawlsian ethics?