This problem is about a little pig named Benny. Benny was given an array of N integers and another separate integer X. Benny has to find the number of subsets (not necessarily contiguous) of A such that Bitwise XOR of all elements contained within the subset evaluates to X.
Probably, you have already guessed that she missed a lot of classes and is not able to solve her homework now. Therefore, she asks you to help her. Find the number of subsets of A such that Bitwise XOR of all elements of the subset will be equal to X.
Input format
The first line of the input contains two space separated integers, N and X.
The next line contains N integers denoting the array A.
Output format
Print in a single line an answer to the problem. As the answer might be large, output it modulo 107 + 7.
Constraints
- 1 ≤ N ≤ \(10\)3
- 0 ≤ Ai ≤ 2\(20\)
Note
The amount of Ai > 2\(10\) is not more than \(20\).
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