input: Write a python function to check for duplicates in a list.
  assert check_duplicates([1, 2, 3, 4, 5]) == False
  assert check_duplicates([1, 2, 3, 2, 5]) == True
  assert check_duplicates([10, 20, 30, 40, 50]) == False
  assert check_duplicates([10, 20, 30, 20, 10]) == True
output: def check_duplicates(lst):
      return len(lst) != len(set(lst))