Contribution #755

Problem: ru/2.6.16

Added 2.6.16 2.6.18 2.6.20 2.6.21 2.6.25

Editor: Aliaksandr Melnichenka ( @astrosander )

Time: December 9, 2023 at 03:59 PM

GitHub commit: c7b12910a6a60f1c2081262cfb7d6ac0e324e457

+173 -0 lines changed