[jl2718]

What's the language on the one-liner? I know nothing about J, but it doesn't seem to run. Sorry; just a bit fascinated.

[jonahx]

It's J also. Link which will run:

https://tio.run/##JYyxDoJAEER7v@LpWdzl4iJwoJiY6HcIlSERG0sKDb...