How to make it so that if there are 3 identical numbers in a row in the list, then they are deleted?

Question

Python

a = [1, 2, 3, 3, 3]
How to make it so that if the list contains at least 3 identical numbers in a row, then they are deleted? And you also need to record how many elements were deleted. It is desirable that the method be without using pip

Answer 1

Cycle. That's just a question, but if after deletion there are again 3 in a row, also delete?
For example, Should it output a = [1, 1, 1] or a = []? If the first, then something like this ...
a = [1, 1, 2, 2, 2, 1]

our_list = [1, 2, 3, 3, 3]
#идём от конца списка к началу - так удаление повлияет только на уже обработанные элементы списка.
for i in range(len(our_list) - 3, 0, -1): 
  if our_list[i:i+3] ==  [ our_list[i] ] * 3: #сравниваем фрагмент списка с повтором элемента трижды
    del our_list[i:i+3]

print(our_list)