Starting from step $0$, Marisa needs to climb up to step $n$ in order to reach the Hakurei Shrine atop the mountain. However, as time goes by, there are $m$ steps that have deteriorated, and if she steps on them, she will fall. If she takes $2$ or $3$ steps at a time, how many ways can she reach the shrine safely?
### Input
- The first line consists of two integers $n$ and $m$.
- The second line contains $m$ integers $M_i$, which represent the list of deteriorated steps.
### Output
- Print a single integer, modulo $998244353$, since the answer can be very large.
### Constraints
- $1 \le n \le 10^{18}$.
- $1 \le m \le 10^4$.
- $1 \le M_i \le n$.
### Example
Input:
```
8 3
1 2 4
```
Output:
```
2
```
