You are given a tree that contains n vertices. Count the number of decompositions of the tree into paths modulo 998244353.
A tree decompositions in paths is valid if each vertex belongs to exactly one path (a path can be only a single vertex).
Two decompositions are different if there are two vertices v and u that belong to the same path in one of the decompositions but two distinct paths in the other.
Input format
Output format
Print an integer that denotes the number of decompositions of the tree into paths modular 998244353.
These are four decompositions:
(1),(2),(3)
(1,2),(3)
(1,3),(2)
(2,1,3).