AT_abc453_e [ABC453E] Team Division
Description
Divide $ N $ players, player $ 1 $ , player $ 2 $ , $ \ldots $ , player $ N $ , into two (distinguishable) teams $ A $ and $ B $ satisfying all of the following conditions.
- Each team consists of at least one player.
- Each player belongs to either team $ A $ or team $ B $ , but not both.
- The number of players in the team that player $ i $ belongs to is at least $ L_i $ and at most $ R_i $ .
Find the number of ways to divide the players satisfying the conditions, and output the count modulo $ 998244353 $ .
Two divisions are considered different if there exists a player who belongs to different teams in the two divisions.
Input Format
The input is given from Standard Input in the following format:
> $ N $ \
> $ L_1 $ $ R_1 $\
> $ L_2 $ $ R_2 $\
> $ \vdots $\
> $ L_N $ $ R_N $
Output Format
Output the number of valid divisions, modulo $ 998244353 $ .
Explanation/Hint
### Sample Explanation 1
The following two divisions satisfy the conditions.
- Player $ 1 $ : Team $ A $ , Player $ 2 $ : Team $ B $ , Player $ 3 $ : Team $ B $
- Player $ 1 $ : Team $ B $ , Player $ 2 $ : Team $ A $ , Player $ 3 $ : Team $ A $
Since $ 2 $ modulo $ 998244353 $ is $ 2 $ , output $ 2 $ .
### Sample Explanation 2
There are $ 30 $ valid divisions.
### Constraints
- $ 2\leq N\leq 2\times 10^5 $
- $ 1\leq L_i\leq R_i\leq N-1 $
- All input values are integers.