Counting occurrence streaks of '2's between three '1's

[Hein Htut Oo]

Hi, I have a list of numbers which are mostly '1's and '2's, and sometimes '3's. Currently, I have formulas to count how many '2's occur before a '1' occur. I also have formula to count how many '2's occur between two '1's. I want to count how many '2's occur between THREE '1's. I am really stuck on this, any help would be hugely appreciated!! I have attached an example excel file to show the formulas I already have.

[Kaper]

Pleas give expected (manualy calculated) result for some (let's say a dozen or two) first results in column L.

[Hein Htut Oo]

My bad, I just put the expected values in the same column. Please check it out!