I submitted Mathsticks 10 yesterday. Squeezing it in 10 lines was difficult, but 72 characters limit was super difficult :D. When I needed to fix randomisation, I dropped changing the colour of the border as I had no free space at all... and then I realized I can make some shuffling still and squeeze it back "between the lines"! This is what I love about 10-liners the most :D. Thanks for the competition, looking forward for playing other entries!