However, I am posting to celebrate my 500th problem solved (just a few more toughies to go now). It means I managed the goal I've had for a while now to solve 500 problems in (at most) 500 days since starting Project Euler. Done, with a few days to spare. It's been a long, hard, fascinating and instructive journey, thanks to all the problem setters.
Встречаются же люди... мне остаётся лишь только им завидовать.