Solve the programming task below in a Python markdown code block.
Bob is a lazy man. 

He needs you to create a method that can determine how many ```letters``` and ```digits``` are in a given string.



Example:

"hel2!lo" --> 6

"wicked .. !" --> 6

"!?..A" --> 1
Also feel free to reuse/extend the following starter code:
```python
def count_letters_and_digits(s):
```