My farm contains 50 pigs. It has been said by the veterinarian that tomorrow starting at 8:00 am, 2 pigs will die every hour because of a disease that has struck them. There is nothing I can do about it. However, if my vet gets to give them the medicine she has been working on, they will be 100% cured.
At 9:30 am the next morning, the vet tells me that she finishes the antidote and will be here at the farm by 2:20 am after an appointment with other scheduled patients. The phone at my house rang around 10:10 and I answered a call that lasted for 15 minutes.
When I came back, I expected there were dead pigs already but to my surprise, half of the remaining pigs I saw before I answered the call were gone. Maybe they were stolen and eaten. Eh, whoever did that will die because of the disease too so I don't need to teach them a lesson.
At 1:40 am, the vet got a flat tire and told me that she will come here an hour later than the said time before.
At the time when she finally comes, how many pigs can still be saved?