An integer N (3 ≤ N ≤ 2047), where N is odd.
An N x N grid of characters where each character is either 'o' or 'x'.

### Example Input:

```
5
oxooo
oxooo
oxooo
xxxxx
oxooo
```

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