Value of --pw-max must be smaller or equal to 32

[rico]

which math field do I need to know?

Multiplication and comprehension of the resulting mind-bendingly large number of 10 to the power of 77.

And that time is finite.

[epixoip]

Just basic, elementary maths. Keyspace for this attack is 16^64. Fastest GPU (Titan X) can crack sha256 at 2.2 GH/s. This means you would need 1.6x10^54 Titan X GPUs to crack this password in one million years. And you're trying to do it with a single CPU.

Is that enough to convince you that it is impossible?

[rico]

To be fair, there's a 50:50 chance it'll only take those cards half a million years, not the full million.