Maximum Sum With Exactly K Elements

You are given a 0-indexed integer array nums and an integer k. Your task is to perform the following operation exactly k times in order to maximize your score:

Select an element m from nums.
Remove the selected element m from the array.
Add a new element with a value of m + 1 to the array.
Increase your score by m.
Return the maximum score you can achieve after performing the operation exactly k times.

class Solution(object):
    def maximizeSum(self, nums, k):
        totalSum = maximum = max(nums)
        for i in range(1, k):
            totalSum += (maximum + 1)
            maximum += 1
        return totalSum