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

You're given strings jewels representing the types of stones that are jewels, and stones representing the stones you have. Each character in stones is a type of stone you have. You want to know how many of the stones you have are also jewels.
Letters are case sensitive, so "a" is considered a different type of stone from "A".
 
Please complete the following python code precisely:
```python
class Solution:
    def numJewelsInStones(self, jewels: str, stones: str) -> int:
```