Unhasshable type 'list'

[buran]

SUBJEK is list of lists, so it's not hashable. That is exactly what the error says...

>>> my_list = [[1,2], [3,4]]
>>> set(my_list)
Traceback (most recent call last):
  File "<stdin>", line 1, in <module>
TypeError: unhashable type: 'list'

I don't see the point of adding set(SUBJEK). i.e. kata is str, elements in SUBJEK are of type list