An integer N (1 ≤ N ≤ 100), representing some quantity or size.  
An integer K (1 ≤ K ≤ 100000), representing another quantity.  
A list of N integers, where each integer is between 1 and K, and the list is strictly increasing.

### Example Input:

```
2
5
2 3
```

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