input: Write a python function to find the difference between two sets.
  assert find_difference({2, 4, 6, 8, 10}, {3, 5, 7, 9}) == {2, 4, 6, 8, 10}
  assert find_difference({1, 2, 3}, {2, 3, 4}) == {1}
  assert find_difference({10, 20, 30}, {10, 30, 40}) == {20}
output: def find_difference(set1, set2):
      return set1 - set2