There are $n(\geq 3)$ white balls arranged in a circle, numbered $1, 2, \dots, n$. You need to paint all these balls black. The operation is as follows:
- Choose a ball that has not been chosen before (either white or black) uniformly at random.
- Paint the chosen ball and its two adjacent balls black.
- If all white balls are painted black, the process ends.
Calculate the expected number of operations to paint all white balls black. The answer should be taken modulo 998244353.
Input
A single positive integer $n$, representing the number of white balls.
Output
A single integer representing the expected number of operations, modulo 998244353.
Examples
Input 1
4
Output 1
2
Note 1
After the first operation, only one white ball remains. Next, there are two black balls and one white ball that can be chosen; regardless of which one is chosen, all balls will be painted black.
Input 2
5
Output 2
499122179
Constraints
For $40\%$ of the data, $n \leq 10$.
For $100\%$ of the data, $n \leq 5000$.