input: Write a function to find unique elements in a list.
  assert find_unique_elements([1, 2, 2, 3, 4, 4, 5]) == [1, 2, 3, 4, 5]
  assert find_unique_elements([10, 10, 10, 10]) == [10]
  assert find_unique_elements([1, 3, 5, 7, 9, 1, 3, 5, 7, 9]) == [1, 3, 5, 7, 9]
output: def find_unique_elements(lst):
      return list(set(lst))