There is an array of positive integers given. You have to find an integer denoting the maximum XOR subset value in the given array.

Write a function `solve`

that have the following parameter(s):

1.) *arr = an array of integer*

**Example**

Input:

`arr = [1, 2, 3]`

Output:

`3`

**Explanation**

The subset {1, 2} has maximum subset XOR value.

**Constraints**

• Number of elements in an array will be greater than or equal to 1 and less than or equal to 10.

• Every element in an array will be greater than or equal to 1 and less than or equal to 10000.