https://scalachallenge.com/2026-10-141.0 https://scalachallenge.com/rules2026-10-140.4 https://scalachallenge.com/facts2026-10-140.8 https://scalachallenge.com/partner2026-10-140.3 https://scalachallenge.com/c/7-day-scala-kata-streak2026-10-140.6 https://scalachallenge.com/c/model-it-with-a-case-class2026-10-140.6 https://scalachallenge.com/c/14-day-immutable-habit2026-10-140.6