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 $$$n$$$ ($$$1 \leq n \leq 150\,000$$$).
The second line contains $$$2n$$$ integers $$$a_1, a_2, \ldots, a_{2n}$$$ ($$$1 \leq a_i \leq 10^9$$$) — elements of array $$$a$$$.
Print one integer — the answer to the problem, modulo $$$998244353$$$.
1 1 4
6
2 2 1 2 1
12
3 2 2 2 2 2 2
0
5 13 8 35 94 9284 34 54 69 123 846
2588544
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 $$$a$$$:
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