input: Write a python function to remove duplicate elements from a list and return the result as a set.
  assert remove_duplicates([1, 2, 2, 3, 4, 4, 5]) == {1, 2, 3, 4, 5}
  assert remove_duplicates([10, 20, 20, 30, 40, 40, 50]) == {10, 20, 30, 40, 50}
  assert remove_duplicates([1, 1, 1, 1, 1, 1, 1]) == {1}
output: def remove_duplicates(lst):
      return set(lst)