Before revision:  For other parameters , like mortality rate or the number of respiratory ventilators per million of inhabitants, we take values typical for developed countries. We simulate populations of 10^5-10^6 people. We compare different strategies: do-nothing , social distancing , reduction of social mixingand lockdown, assuming that there is no vaccine and no efficient medicine .
After revision:  For other parameters , like mortality rate or the number of respiratory ventilators per 100000 inhabitants, are chosen to simulate the real values for the USA and Poland. In the simulations we compare ` do-nothing , social distancing , reduction of social mixingand lockdown, assuming that there is no vaccine and no efficient medicine .