Canonicalized Input Description:

An integer H (1 ≤ H ≤ 10), representing some quantity or size.
An integer W (1 ≤ W ≤ 10), representing some quantity or size.
A list of H strings, each of length W, consisting of characters '.' and '#'.

### Example Input:

```
2
2
#.
.#
```

### Function Signature:
Write a function f(H, W, A) that takes in the input.
```python
def f(H: int, W: int, A: List[str]):
    '''
    H: an integer
    W: an integer
    A: a list of strings
    '''
```