input: Write a python function that deletes all tuples whose length equals k.
  assert remove_tuples([(4, 5), (4,), (8, 6, 7), (1,), (3, 4, 6, 7)], 1) == [(4, 5), (8, 6, 7), (3, 4, 6, 7)]
  assert remove_tuples([(4, 5), (4, 5), (6, 7), (1, 2, 3), (3, 4, 6, 7)], 2) == [(1, 2, 3), (3, 4, 6, 7)]
  assert remove_tuples([(1, 4, 4), (4, 3), (8, 6, 7), (1,), (3, 6, 7)], 3) == [(4, 3), (1,)]
output: def remove_tuples(lst, k):
      return [tup for tup in lst if len(tup) != k]