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

Given an array of positive integers nums, return the number of distinct prime factors in the product of the elements of nums.
Note that:

A number greater than 1 is called prime if it is divisible by only 1 and itself.
An integer val1 is a factor of another integer val2 if val2 / val1 is an integer.

 
Please complete the following python code precisely:
```python
class Solution:
    def distinctPrimeFactors(self, nums: List[int]) -> int:
```