An integer H (2 ≤ H ≤ 200), representing some quantity or size.
An integer W (2 ≤ W ≤ 200), representing some quantity or size.
H lines of strings of length W, where each character in the string is one of {'@', '$', '%', '.', '#'}. 

### Example Input:

```
2 4
%.@$
..$$
```

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