  In this paper, we study the number of limit cycles of a piecewise smooth
differential system separated by one or two parallel straight lines or rays
formed by a nilpotent center or degenerate center and linear saddle. Piecewise
linear differential systems separated by one or two parallel straight lines
with one of the subsystems of type nilpotent center and other subsystems of
type linear saddle can have at most two limit cycles and there are systems in
these classes having one limit cycle. The limit cycle in particular consists of
saddle separatrices of the subsystem.
