#D4878. Divide and Sum
Divide and Sum
Divide and Sum
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) = ∑_{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.
Input
The first line contains a single integer n (1 ≤ n ≤ 150 000).
The second line contains 2n integers a_1, a_2, …, a_{2n} (1 ≤ a_i ≤ 10^9) — elements of array a.
Output
Print one integer — the answer to the problem, modulo 998244353.
Examples
Input
1 1 4
Output
6
Input
2 2 1 2 1
Output
12
Input
3 2 2 2 2 2 2
Output
0
Input
5 13 8 35 94 9284 34 54 69 123 846
Output
2588544
Note
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:
- p = [1], q = [4], then x = [1], y = [4], f(p, q) = |1 - 4| = 3;
- p = [4], q = [1], then x = [4], y = [1], f(p, q) = |4 - 1| = 3.
In the second example, there are six valid partitions of the array a:
- p = [2, 1], q = [2, 1] (elements with indices 1 and 2 in the original array are selected in the subsequence p);
- p = [2, 2], q = [1, 1];
- p = [2, 1], q = [1, 2] (elements with indices 1 and 4 are selected in the subsequence p);
- p = [1, 2], q = [2, 1];
- p = [1, 1], q = [2, 2];
- p = [2, 1], q = [2, 1] (elements with indices 3 and 4 are selected in the subsequence p).
inputFormat
Input
The first line contains a single integer n (1 ≤ n ≤ 150 000).
The second line contains 2n integers a_1, a_2, …, a_{2n} (1 ≤ a_i ≤ 10^9) — elements of array a.
outputFormat
Output
Print one integer — the answer to the problem, modulo 998244353.
Examples
Input
1 1 4
Output
6
Input
2 2 1 2 1
Output
12
Input
3 2 2 2 2 2 2
Output
0
Input
5 13 8 35 94 9284 34 54 69 123 846
Output
2588544
Note
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:
- p = [1], q = [4], then x = [1], y = [4], f(p, q) = |1 - 4| = 3;
- p = [4], q = [1], then x = [4], y = [1], f(p, q) = |4 - 1| = 3.
In the second example, there are six valid partitions of the array a:
- p = [2, 1], q = [2, 1] (elements with indices 1 and 2 in the original array are selected in the subsequence p);
- p = [2, 2], q = [1, 1];
- p = [2, 1], q = [1, 2] (elements with indices 1 and 4 are selected in the subsequence p);
- p = [1, 2], q = [2, 1];
- p = [1, 1], q = [2, 2];
- p = [2, 1], q = [2, 1] (elements with indices 3 and 4 are selected in the subsequence p).
样例
1
1 4
6
</p>