Contribution #1442

Problem: ru/1.2.21

Updated 1.2.20 and 1.2.21 solutions

Editor: Aliaksandr Melnichenka ( @astrosander )

Time: June 18, 2024 at 12:32 PM

GitHub commit: f8faa08e68860cca28716f1a2d45ba8008a781b7

+129 -213 lines changed