you should see a link "Edit Kata" in the top right corner of this page (on the left of "add to collection"). From there you can make the needed modifications.

Reference solution is incorrect, as pointed out by @konakona above:

(vec![2, 2, 101, 2], 6),

solved ;)

I've just removed the apology, but I'll wait for the original author to change the title to what he/she thinks is best.