input: Write a python function that takes a list of integers and an integer k. The function should return the minimum number of operations required to ensure that all elements in the list are no less than k, where each operation removes one instance of the smallest element in the list.
  
  Examples:
  
  >>> nums = [2, 11, 10, 1, 3], k = 10
  3
  >>> nums = [1, 1, 2, 4, 9], k = 1
  0
  >>> nums = [1, 1, 2, 4, 9], k = 9
  4
  
  
  Constraints:
  - The length of nums is between 1 and 50 inclusive.
  - Each element of nums is between 1 and 10^9 inclusive.
  - k is between 1 and 10^9 inclusive.
  - The array nums contains at least one element that is greater than or equal to k.
output: def min_operations_to_ensure_minimum(nums, k):
      nums.sort()
      operations = 0
      while nums and nums[0] < k:
          nums.pop(0)
          operations += 1
      return operations