The mathematical model created for the needsthis of the research was namedcalled S I SI (S — savesaved, I — infected, SI — have been saved, but were infected in the building were infected)building). There are two possibilities at the entrance: saved and infected. People who came to the building infected left the dose of the virus in their place. The amount of virus left specifies the parameter named virus. A person staying in the field where is athe virus is can change status from S to SI with calculated probability:

P = a * virus_on / 100

where a is a parameter named status_I, virus_on is the amount of the virus onin that field. Only people with S status S can change it.