Example Brain-even: https://asciinema.org/a/MEmDbWD0arL9omHIwrkglIjo7
Example Brain-calc: https://asciinema.org/a/6PxpfUGvTOZRdkhfCZ3z1MlHB
Example Brain-gcd: https://asciinema.org/a/IUZeUnFUUOP8a9aSOR2PR1FU9
Example Brain-progression: https://asciinema.org/a/TMoPkgk4n8gDsqdCV400oK497
Example Brain-prime: https://asciinema.org/a/4kYnoLZLjQEt3xhiuy9jlbQ7N