Given an array of integers `arr`.

We want to select three indices `i`, `j` and `k` where `(0 <= i < j <= k < arr.length)`.

Let's define `a` and `b` as follows:

- `a = arr[i] ^ arr[i + 1] ^ ... ^ arr[j - 1]`
- `b = arr[j] ^ arr[j + 1] ^ ... ^ arr[k]`

Note that ^ denotes the bitwise-xor operation.

Return the number of triplets (`i`, `j` and `k`) Where `a == b`.

Example 1:

    Input: arr = [2,3,1,6,7]
    Output: 4
    Explanation: The triplets are (0,1,2), (0,2,2), (2,3,4) and (2,4,4)

Example 2:

    Input: arr = [1,1,1,1,1]
    Output: 10

Constraints:

- `1 <= arr.length <= 300`
- `1 <= arr[i] <= 108`