Instructions: 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.
Input: [463, 228, 473, 145, 347, 39, 90, 233, 455, 128, 219, 239, 336, 467, 69, 493, 339, 457, 120, 354]
Output:
[463, 228, 473, 145, 347, 493, 90, 233, 455, 128, 219, 239, 336, 467, 69, 39, 339, 457, 120, 354]