B"You are given two integers n and k . For an array of length n , let's define its cost as the maximum number of contiguous subarrays of this array that can be chosen so that: For example, if n = 10 , k = 3 and the array is [1, 2, 1, 3, 2, 3, 2, 3, 1, 3] , its cost is 2 because, for example, we can choose the subarrays from the 2 -nd element to the 4 -th element and from the 7 -th element to the 9 -th element, and we can show that it's impossible to choose more than 2 subarrays. Calculate the sum of costs over all arrays of length n consisting of integers from 1 to k , and print it modulo 998244353 . The only line of the input contains two integers n and k ( 2 <= k <= n <= 4000 ). Print one integer -- the sum of costs of all arrays of length n consisting of integers from 1 to k taken modulo 998244353 . "...