Could you please help me with this linear discrete time model problem?

We will model the spread of an infectious disease in a population. There will be three sub- populations: the susceptible individuals (S), who can catch the disease; the infected individuals (I); and the immune individuals (R), who have acquired immunity by having had the disease. - Each day, 3% of susceptible individuals get infected. - On average, a person remains infected for about three weeks, so each day, 5% of infected individuals recover. Four in ve, or 80%, of those who recover each day have developed an immunity; one in ve, or 20%, of those who recover each day will not be immune, and will immediately be susceptible again. - Each day, 2% of infected individuals die from the infection. - Each day, 6% of immune individuals will lose their immunity and become susceptible again. - Each day, 1% of immune individuals die from lingering complications of the disease. a} (4 pts) Draw a compartment diagram for this model. Be sure to include all ows, and label them with the total ow rates. b} (6 pts) Write down the matrix of this model