Canonicalized Input Description:

An integer N (6 ≤ N ≤ 6000), representing some quantity or size.
An integer M (0 ≤ M ≤ N), representing another quantity or size.
An integer X (0 ≤ X ≤ 6), representing another quantity or size.
An integer Y (0 ≤ Y ≤ 12), representing another quantity or size, with the additional constraint that 2X + Y = 12.
A list of N integers, where each integer is between 1 and 6000.
A list of M integers, where each integer is between 1 and 3000, with the additional constraint that each corresponding integer in the first list minus this integer is between 1 and 3000.

### Example Input:

```
18 8 3 6
4
3
3
3
3
2
2
2
1
1
1
1
1
2
2
3
3
3
1
1
1
1
1
1
1
1
```

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