Arn, 19 bytes

ʠ|<┐¾ý6TÏ└&ã£L>gcmº

I would provide the unpacked form, but it's rather trivial to decode adds to the challenge if you have to decode it yourself. Not terribly difficult, but it requires you to access the source code. The flag you want is:

7.9228162514264337593543950336e+28

this was done in the online interpreter. This shouldn't be too difficult, and multiple inputs should theoretically work. However, I encourage you to try and figure out the one I used (you will know immediately if you found the right one).