Contribution #1466

Problem: ru/1.3.21

Added 1.3.15-1.3.17&1.3.20-21;Updated 1.3.18-19

Editor: Aliaksandr Melnichenka ( @astrosander )

Time: June 20, 2024 at 06:26 AM

GitHub commit: d964aa11241f135cd508d1c64fff1522d7a1c627

+81 -7 lines changed