Contribution #779

Problem: ru/11.1.17

Updated solutions 11.1.5 11.1.7 11.1.17 11.1.21 11.1.25

Editor: Aliaksandr Melnichenka ( @astrosander )

Time: December 24, 2023 at 01:31 PM

GitHub commit: ccd5c30bdc1097adee86a6e1842a3545e43f4fbe

+187 -200 lines changed