input: 
  from typing import List
  
  def min_length_special_subarray(nums: List[int], k: int) -> int:
      """
      Given a list of non-negative numbers and an integer k, find a subarray.
  
      A subarray is termed valid if the bitwise OR of its elements meets or exceeds k.
  
      Determine the smallest possible length of such a non-empty subarray in nums. Return -1 if no valid subarray can be found.
  
      Examples:
      >>> nums = [1,2,3], k = 2
      1
      >>> nums = [2,1,8], k = 10
      3
      >>> nums = [1,2], k = 0
      1
  
      Constraints:
      1 <= nums.length <= 50
      0 <= nums[i] <= 50
      0 <= k < 64
      """
  
output:     
      n = len(nums)
      min_length = float('inf')
  
      for i in range(n):
          current_or = 0
          for j in range(i, n):
              current_or |= nums[j]
              if current_or >= k:
                  min_length = min(min_length, j - i + 1)
                  break
  
      return min_length if min_length != float('inf') else -1
  