k1 = R0
k2 = a0
k3 = a1
k4 = k
k5 = u
k6 = lambda
k7 = d
k8 = beta
k9 = gamma
k10 = alpha
k11 = phi
k12 = eta
k13 = pa
k14 = ca
k15 = r
k16 = ba
k17 = p_i
k18 = ci
k19 = bi
k20 = xi
k21 = COMpartment