How can I get the bit-to-bit inversion with Vanilla pure-data?

For example:
Input: 12 (1100) - Output 3 (0011)

I tried with [expr] but it outputs -3, so I made a version with two vanilla abstractions I've written ([int2bin] and [bin2any]) which you can find here https://github.com/alexdrymonitis/miscellaneous_abstractions and [list-drip], which is a vanilla abstraction from the list-abs library.
It might be a bit of an overkill, but it works. Here's the patch bitwise_not.pd
And here's an image for whoever wants to get a glance of the patch:

Thank you!
I thought it was more simple!
I downloaded the patch and dowload int2bin and bin2any, but I don't have the list-drip object. How could I get it?

@fabio-C It
can be made for vanilla like this.......
list-drip.pd
David.

@fabio-C It's a library of vanilla abstractions called list-abs. It's on deken, I think