题目描述
Problem Description
Given an integer \( n \), count the number of unlabeled rootless trees with \( n \) nodes, and output the result modulo \( 998244353 \).
Input Format
A single line containing a positive integer \( n \).
Output Format
A single line containing an integer representing the answer.
Sample Input and Output
Sample Input #1
7
Sample Output #1
11
Sample Input #2
27
Sample Output #2
751065460
Notes
Data Range:
- For 30% of the test cases, \( 1 \leq n \leq 1000 \).
- For 100% of the test cases, \( 1 \leq n \leq 2 \times 10^5 \).
Although an algorithm with time complexity \( \Theta(n \log^2 n) \) can pass, it is not meaningful. It is recommended to implement an algorithm with time complexity \( \Theta(n \log n) \).
输入格式
见题面 Input 部分
输出格式
见题面 Output 部分
样例输入
7
样例输出
11