题目描述
Problem Description
Determine the number of distinct labeled unrooted trees with $n$ nodes, such that for any node $x$, there exists a node $y$ such that $x$ and $y$ are connected by an edge and $|x - y| = 1$. The answer should be modulo $998244353$.
Input Format
A single line containing a positive integer $n$.
Output Format
A single line containing an integer, the required answer.
Sample Input and Output
Sample Input #1
4
Sample Output #1
4
Sample Input #2
209
Sample Output #2
21754876
Sample Input #3
5
Sample Output #3
11
Sample Input #4
6
Sample Output #4
56
Notes
[Sample Explanation #1]

The four trees that meet the criteria in Sample #1 are shown in the image above.
[Data Range]
This problem includes 20 test cases, each worth 5 points.
| Test Case Number | Range of $n$ |
|---|---|
| $1 \sim 2$ | $\leq 7$ |
| $3 \sim 4$ | $\leq 14$ |
| $5 \sim 8$ | $\leq 30$ |
| $9 \sim 12$ | $\leq 10^3$ |
| $13 \sim 20$ | $\leq 10^5$ |
For all test cases, $n$ is a positive integer and $2 \leq n \leq 10^5$.
输入格式
见题面 Input 部分
输出格式
见题面 Output 部分
样例输入
4
样例输出
4