Recently, Colin has been learning the relationship between sets and bitmasks. We can use binary numbers (bitmasks) to represent sets, and if some bits are 1 in the bitmask, then it means that the sets include the elements corresponding to the indices of these bits.
Now Colin has $$$n$$$ non-negative integers $$$a_1, a_2, \cdots, a_n$$$ and all these integers are less than $$$2^k$$$. Now Colin tries to use the concept of bitmasks and sets to understand the relationship between these integers.
For a non-negative integer $$$x \in\left[0,2^k\right)$$$, Colin defines that $$$a_i$$$ is feasible with $$$a_j$$$ under the augmentation of $$$x$$$, if and only if the set corresponding to the bitmask $$$a_i+x$$$ is a subset of the set corresponding to the bitmask $$$a_j+x$$$. Then Colin uses $$$f(x)$$$ to represent the number of all the pairs $$$(i, j)$$$ such that $$$a_i$$$ is feasible with $$$a_j$$$ under the augmentation of $$$x$$$.
Now Colin would like to ask you to calculate the sum of all the $$$f(x)$$$, modulo $$$998244353$$$ .
Formally, please calculate
$$$$$$ \left(\sum_{x=0}^{2^k-1} f(x)\right) \bmod 998244353 $$$$$$
The first line contains two integers $$$n,k~(1\le n\le 10^6, 1\le k\le 20)$$$, representing the number of integers Colin has and all of these integers are less than $$$2^k$$$.
The following line contains $$$n$$$ integers $$$a_1, a_2, \cdots, a_n\left(0 \leq a_i \lt 2^k\right)$$$.
Output a single integer, representing the answer.
2 22 0
10
$$$f(0)=3:(1,1),(2,1),(2,2)$$$
$$$f(1)=3:(1,1),(2,1),(2,2)$$$
$$$f(2)=2:(1,1),(2,2)$$$
$$$f(3)=2:(1,1),(2,2)$$$
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