Please solve the programming task below using a self-contained code snippet in a markdown code block.

You are given two integers, n and k.
An array of distinct positive integers is called a k-avoiding array if there does not exist any pair of distinct elements that sum to k.
Return the minimum possible sum of a k-avoiding array of length n.
 
Please complete the following python code precisely:
```python
class Solution:
    def minimumSum(self, n: int, k: int) -> int:
```