Next time I have a long flight, I can now go through Project Euler and stop when I'm right. Having solutions is nice to have. One interesting potential mode w

Next time I have a long flight, I can now go through Project Euler and stop when I'm right. Having solutions is nice to have. One interesting potential mode would be to (as suggested below) encrypt the solutions and switch --verify to --attempt, then keep track of # of attempts for scorekeeping.