Pm-saturated graphs with minimum size

By Pm we denote a path of order m. A graph G is said to be Pm - saturated if G has no subgraph isomorphic to Pm and adding any new edge to G creates a Pm in G. In 1986 L. Kaszonyi and Zs. Tuza considered the following problem: for given m and n find the minimum size sat(n; Pm) of Pm-saturated graph and characterize the graphs of Sat(n; Pm) - the set of Pm-saturated graphs of minimum size. They have solved this problem for [formula].