<b_jonas> slashlearn euclid//Euclid is a short geeky game in which the goal is to do Euclidean compass and straightedge constructions in as few steps as possible. It runs in the browser, found at "http://www.euclidthegame.com/". It was popular among #esoteric regulars in 2016-07.

#!/hackenv/bin/shebang_args_or_input perl -p
s/([^0-9])([0-9]+)/$1 x $2/ge