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

Given an integer n, return true if it is possible to represent n as the sum of distinct powers of three. Otherwise, return false.
An integer y is a power of three if there exists an integer x such that y == 3x.
 
Please complete the following python code precisely:
```python
class Solution:
    def checkPowersOfThree(self, n: int) -> bool:
```