Challenge 10 - Find the missing numbers

You have a bag containing tiles with numbers [1, 2, 3, …, n] written on them. Each number appears exactly once, so there are n tiles and n numbers. Now, without looking, k number tiles are randomly picked out of the bag and discarded. Create a function that takes in a list and k, and returns the missing numbers in ascending order (from smallest to greatest).

For example, ([1, 2, 4, 5, 6, 7, 8, 10], 2) should return [3, 9].
 

Input: 
K: