Contribution #219

Problem: ru/2.5.21

Added 1.3.18 1.3.27 1.4.18 1.4.6 2.5.21 2.6.49 4.1.17

Editor: Aliaksandr Melnichenka ( @astrosander )

Time: October 15, 2023 at 03:41 PM

GitHub commit: c4e8641d884a1024bedf20d53a3e39e3918e1b2d

+243 -49 lines changed