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

You are given coordinates, a string that represents the coordinates of a square of the chessboard. Below is a chessboard for your reference.

Return true if the square is white, and false if the square is black.
The coordinate will always represent a valid chessboard square. The coordinate will always have the letter first, and the number second.
 
Please complete the following python code precisely:
```python
class Solution:
    def squareIsWhite(self, coordinates: str) -> bool:
```