In this task, you are given a list of unique integers you need to swap the positions of maximum and minimum element in the list and return the updated list.
Q: [424, 356, 298, 311, 433, 419, 23, 69, 27, 499, 108, 140, 190, 442, 196, 383, 445, 93, 20, 490]
A: 
[424, 356, 298, 311, 433, 419, 23, 69, 27, 20, 108, 140, 190, 442, 196, 383, 445, 93, 499, 490]