Bob has a random number generator, it will generate 

 with probability 

.  
 Now Bob will do the following operations: 
 Step 1. Generate a number 

 by random number generator. 
 Step 2. If 

 is the largest number among the generated numbers (i.e., 

 is no smaller than any previously generated numbers), go to step 1, otherwise, go to step 3. 
 Step 3. If Bob generates 

 numbers totally, Bob will get 

 score. 
 Now Bob wants to know the expected value of the score he will get. 
 If the answer is irreducible fraction 

, you need to output an integer 

 in [0,998244352] which satisfies 

. It's guaranteed that 

.