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

.