B"You are given an array a of length 2n . Consider a partition of array a into two subsequences p and q of length n each (each element of array a should be in exactly one subsequence: either in p or in q ). Let's sort p in non-decreasing order, and q in non-increasing order, we can denote the sorted versions by x and y , respectively. Then the cost of a partition is defined as f(p, q) = sum_{i = 1}^n |x_i - y_i| . Find the sum of f(p, q) over all correct partitions of array a . Since the answer might be too big, print its remainder modulo 998244353 . The first line contains a single integer n ( 1 <= q n <= q 150 ,000 ). The second line contains 2n integers a_1, a_2, ldots, a_{2n} ( 1 <= q a_i <= q 10^9 ) -- elements of array a . Print one integer -- the answer to the problem, modulo 998244353 . Two partitions of an array are considered different if the sets of indices of elements included in the subsequence p are different. In the first example, there are two correct partitions of the array a : In the second example, there are six valid partitions of the array a : "...