An integer N (2 ≤ N ≤ 10^5), representing some quantity or size. N is even.
A list of integers V of size N, where each integer is between 1 and 1e5.

### Example Input:

```
4
3 1 3 2
```

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