# Shrink the Array fsshakkhor Criterion 2020 Round 2
Limits 500ms, 256 MB

You have an array of size N which contains positive integers. You can apply the following operation on the array.

• You select an index i (1 ≤ i < size_of_current_array).
• Apply A[i + 1] = A[i + 1] XOR A[i].
• Remove the i'th element from the array.

You have to apply this operation exactly K times on the array. Finally, you will get an array of size (N - K). You have to minimize the maximum element of the final array.

## Input

The first line contains two integers N (2 ≤ N ≤ 50000) and K (1 ≤ K < min(51,N)).

The next line contains N integers Ai (1 ≤ Ai ≤ 109), denoting the elements of the array.

## Output

Print the answer in a single line.

## Sample

InputOutput
3 1
1 2 3

1


If we pick i = 1, we will get [1, 3, 3]. After removal of first element the array will become [3, 3]. Maximum element is 3.

If we pick i = 2, we will get [1, 2, 1]. After removal of second element the array will become [1, 1]. Maximum element is 1.

So, the answer is 1. DP

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