  Piecewise linear differential systems separated by two parallel straight
lines of the type of center-center-Hamiltonian saddle and the
center-Hamiltonian saddle-Hamiltonian saddle can have at most one limit cycle
and there are systems in these classes having one limit cycle. In this paper,
we study the limit cycles of a piecewise smooth differential system separated
by two parallel straight lines formed by nonlinear centers and a Hamiltonian
saddle.
