CF1067E Random Forest Rank
Description
Let's define rank of undirected graph as rank of its adjacency matrix in $ \mathbb{R}^{n \times n} $ .
Given a tree. Each edge of this tree will be deleted with probability $ 1/2 $ , all these deletions are independent. Let $ E $ be the expected rank of resulting forest. Find $ E \cdot 2^{n-1} $ modulo $ 998244353 $ (it is easy to show that $ E \cdot 2^{n-1} $ is an integer).
Input Format
First line of input contains $ n $ ( $ 1 \le n \le 5 \cdot 10^{5} $ ) — number of vertices.
Next $ n-1 $ lines contains two integers $ u $ $ v $ ( $ 1 \le u, \,\, v \le n; \,\, u \ne v $ ) — indices of vertices connected by edge.
It is guaranteed that given graph is a tree.
Output Format
Print one integer — answer to the problem.