Contribution #577

Problem: ru/8.3.4

Added 8.3.1-8.3.6 8.3.9

Editor: Aliaksandr Melnichenka ( @astrosander )

Time: November 13, 2023 at 11:13 AM

GitHub commit: 7485685ed40bb4272292a75dbdaa586969c1ac7c

+272 -59 lines changed