Score : $800$ points

Problem Statement

We have a tree with $N$ vertices, numbered $1, \ldots, N$. For each $i=1,\ldots,N-1$, the $i$-th edge connects Vertex $a_i$ and Vertex $b_i$. An operation on this tree when at most one piece is put on each vertex is defined as follows.

• Simultaneously move every piece to one of the vertices adjacent to the one occupied by the piece.

An operation is said to be good when the conditions below are satisfied.

• Each edge is traversed by at most one piece.
• Each vertex will be occupied by at most one piece after the operation.

Takahashi will put a piece on one or more vertices of his choice. Among the $2^N-1$ ways to put pieces, find the number of ones that satisfy the condition below, modulo $998244353$.

• For every non-negative integer $K$, the following holds.- It is possible to perform a good operation $K$ times.
  • Let $S_K$ be the set of vertices occupied by pieces just after $K$ good operations. Then, $S_K$ is unique.
• It is possible to perform a good operation $K$ times.
• Let $S_K$ be the set of vertices occupied by pieces just after $K$ good operations. Then, $S_K$ is unique.

Constraints

• $2 \leq N \leq 2 \times 10^5$
• $1 \leq a_i \lt b_i \leq N$
• The given graph is a tree.
• All values in input are integers.

Input

Input is given from Standard Input in the following format:

$N$

$a_1$ $b_1$

$\vdots$

$a_{N-1}$ $b_{N-1}$

Output

Print the answer.

3
1 2
1 3

2

Here are the two ways to satisfy the condition.

• Put a piece on Vertex $1$ and Vertex $2$.
• Put a piece on Vertex $1$ and Vertex $3$.

Note that he must put a piece on at least one vertex.

7
1 2
1 3
2 4
2 5
3 6
3 7

0

There might be no way to satisfy the condition.

19
9 14
2 13
1 3
17 19
13 18
12 19
4 5
2 10
4 9
8 11
3 15
6 8
8 10
6 19
9 13
11 15
7 17
16 17

100