input: Write a python function to output the negative numbers from a list.
  assert neg_numbers([-1,4,5,-6]) == -1,-6
  assert neg_numbers([-1,-2,3,4]) == -1,-2
  assert neg_numbers([-7,-6,8,9]) == -7,-6
output: def neg_numbers(lst):
      return tuple(x for x in lst if x < 0)