I've obtained a regex like this: \d\w\w\w\d++(?=\w)|(?<=\d[^\d]\w)\d++|(?<=\w\w\w\d\w\w\w\w\w\w\w\w)\w

for me this regex is bullshit! totally useless!

In order to obtain a good solution, it is important to provide representative examples; it is also important that such examples provide surrounding text that has not to be extracted. We have observed that poor solutions often appear when users provide little variety in examples and no negative examples at all. I suggest to improve the provided examples ad re-execute the solution search.

I'm not affiliated in any way to this project, but there's no need to be a dick about a poor result you got, mostly because you are clearly showing that you didn't read the instructions given on that same page at all.