题目描述
Problem Statement
Find the number of pairs $(P,Q)=((P_1,P_2,\cdots,P_N),(Q_1,Q_2,\cdots,Q_N))$ of permutations of $(1,2,\cdots,N)$ that satisfy the following condition, modulo 998244353.
- For every $i (1 \leq i \leq N-1),$ one of the two conditions below holds.
- P_i < P_{i+1} and Q_i < Q_{i+1}.
- P_i > P_{i+1} and Q_i > Q_{i+1}.
Input
The input is given from Standard Input in the following format:
N
Output
Print the answer.
Constraints
- $2 \leq N \leq 2 \times 10^5$
- All numbers in the input are integers.
Sample Input 1
2
Sample Output 1
2
Two pairs, (P,Q)=((1,2),(1,2)) and (P,Q)=((2,1),(2,1)), satisfy the condition.
Sample Input 2
3
Sample Output 2
10
Sample Input 3
4
Sample Output 3
88
Sample Input 4
10
Sample Output 4
286574791
输入格式
见题面 Input 部分
输出格式
见题面 Output 部分
样例输入
2
样例输出
2