An integer N (1 ≤ N ≤ 300), representing some quantity or size.
A list of lists (2D matrix) A of size N x N, where each element A[i][j] is an integer:
- If i ≠ j: 1 ≤ A[i][j] = A[j][i] ≤ 10^9
- If i == j: A[i][j] = 0

### Example Input:

```
3
0 1 3
1 0 2
3 2 0
```

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