Развязывание верёвок

https://russian-odb.org/2019/06/27/%d1%80%d0%b0%d0%b7%d0%b2%d1%8f%d0%b7%d1%8b%d0%b2%d0%b0%d0%bd%d0%b8%d0%b5-%d0%b2%d0%b5%d1%80%d0%b5%d0%b2%d0%be%d0%ba/