题目描述
Problem Statement
For a positive integer N, a rooted binary tree that satisfies the following conditions is said to be a beautiful binary tree of degree N.
- Each vertex has 0 or 1 written on it.
- Each vertex that is a leaf has 1 written on it.
- It is possible to do the following operation at most N-1 times so that the root has N written on it and the other vertices have 0 written on them.
- Choose vertices u and v, where v must be a child of u or a child of "a child of u." Let $a_u \gets a_u + a_v, a_v \gets 0$, where a_u and a_v are the numbers written on u and v, respectively.
Given N, find the number, modulo 998244353, of beautiful binary trees of degree N.
Input
Input is given from Standard Input in the following format:
N
Output
Print the answer.
Constraints
- $1 \leq N \leq 10^7$
- All values in input are integers.
Sample Input 1
1
Sample Output 1
1
The only binary tree that satisfies the condition is a tree with one vertex whose root has 1 written on it.
Sample Input 2
2
Sample Output 2
6
The binary trees that satisfy the condition are the six trees shown below.
Sample Input 3
222
Sample Output 3
987355927
Sample Input 4
222222
Sample Output 4
675337738
输入格式
见题面 Input 部分
输出格式
见题面 Output 部分
样例输入
1
样例输出
1