An integer N (1 ≤ N ≤ 18), representing some quantity or size.
A list of 2^N integers, each between 1 and 1e9.

### Example Input:

```
2
1
3
2
4
6
8
100
104
```

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